Memory cell array and method of manufacturing same

ABSTRACT

A memory cell array includes a first and second memory cell, a first and second word line and a first bit line. The first memory cell is in a first row in a first direction. The second memory cell is in a second row in the first direction, and is separated from the first memory cell in a second direction. The first word line extends in the first direction and is coupled to the first memory cell. The second word line extends in the first direction and is coupled to the second memory cell. The first bit line extends in the second direction and is coupled to the first and second memory cell. The first memory cell corresponds to a five transistor memory cell. The first memory cell includes a first active region having a first length, and a second active region having a second length.

PRIORITY CLAIM

This application is a continuation of U.S. application Ser. No.16/587,601, filed Sep. 30, 2019, which is a continuation of U.S.application Ser. No. 15/964,492, filed Apr. 27, 2018, now U.S. Pat. No.10,431,576, issued Oct. 1, 2019, which claims the benefit of U.S.Provisional Application No. 62/660,834, filed Apr. 20, 2018, which areherein incorporated by reference in their entireties.

BACKGROUND

The semiconductor integrated circuit (IC) industry has produced a widevariety of digital devices to address issues in a number of differentareas. Some of these digital devices, such as memory macros, areconfigured for the storage of data. For example, in some applications, acache is a particular memory macro that can be used on an IC chip.Furthermore, in some applications, cache can be configured to storerecently used data such that subsequent accesses of recent data can beimplemented by accessing the cache as opposed to accessing memorylocated off of the IC chip (e.g., off-chip). In general, a larger cacheallows more recent data to be stored on-chip resulting in less off-chipmemory data access. The design of smaller memory cells enables denserICs and speeds up overall IC performance. Therefore, alternatives to6-transistor (6T) synchronous random access memory (SRAM) are desired.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a circuit diagram of a memory cell, in accordance with someembodiments.

FIG. 2A is a block diagram of a memory cell array having a plurality ofmemory cells in FIG. 1, in accordance with some embodiments.

FIG. 2B is a circuit diagram of a memory cell array having a pluralityof memory cells in FIG. 1, in accordance with some embodiments.

FIG. 3A is a diagram of a layout design, in accordance with someembodiments.

FIG. 3B is a diagram of a layout design, in accordance with someembodiments.

FIG. 4A is a diagram of a layout design, in accordance with someembodiments.

FIG. 4B is a diagram of a layout design, in accordance with someembodiments.

FIGS. 5A, 5B, 5C, 5D, 5E, 5F, 5G and 5H are diagrams of at least oneintegrated circuit, in accordance with some embodiments.

FIG. 6 is a diagram of a layout design of a memory cell array, inaccordance with some embodiments.

FIG. 7 is a diagram of a layout design of a memory cell array, inaccordance with some embodiments.

FIG. 8 is a diagram of a layout design of a memory cell array, inaccordance with some embodiments.

FIG. 9 is a flowchart of a method of forming or manufacturing a memorycell array, in accordance with some embodiments.

FIGS. 10A-10B are flowcharts of a method of generating a layout designof a memory cell array, in accordance with some embodiments.

FIG. 11 is a block diagram of an integrated circuit (IC) manufacturingsystem and an IC manufacturing flow associated therewith, in accordancewith some embodiments.

FIG. 12 is a block diagram of a system for designing an IC layoutdesign, in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides different embodiments, or examples,for implementing features of the provided subject matter. Specificexamples of components, materials, values, steps, arrangements, or thelike, are described below to simplify the present disclosure. These are,of course, merely examples and are not limiting. Other components,materials, values, steps, arrangements, or the like, are contemplated.For example, the formation of a first feature over or on a secondfeature in the description that follows may include embodiments in whichthe first and second features are formed in direct contact, and may alsoinclude embodiments in which additional features may be formed betweenthe first and second features, such that the first and second featuresmay not be in direct contact. In addition, the present disclosure mayrepeat reference numerals and/or letters in the various examples. Thisrepetition is for the purpose of simplicity and clarity and does not initself dictate a relationship between the various embodiments and/orconfigurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

In accordance with some embodiments, a method of forming a memory cellarray includes generating a first set of tiles extending in a firstdirection and generating a second set of tiles extending in the firstdirection. In some embodiments, each tile of the first set of tilescorresponds to a first layout design of a first set of memory cells. Insome embodiments, each tile of the second set of tiles corresponds to asecond layout design of a second set of memory cells.

In some embodiments, each memory cell of the first set of memory cellscomprises a five transistor (5T) synchronous random access memory (SRAM)memory cell. In some embodiments, each memory cell of the second set ofmemory cells comprises a 5T SRAM memory cell.

In some embodiments, the first set of memory cells are arranged in atleast a first row and a second row of the memory cell array. In someembodiments, the second set of memory cells are arranged in at least athird row and a fourth row of the memory cell array.

In some embodiments, a shape of the first set of tiles or a shape of thesecond set of tiles is non-rectangular which results in smaller standardcells than other designs. In some embodiments, by having smallerstandard cells, the first set of tiles or the second set of tiles can beutilized to manufacture integrated circuits that are smaller than otherintegrated circuits.

The first set of tiles and the second set of tiles alternate with eachother in the second direction. In some embodiments, the second set oftiles is separated from the first set of tiles in the second direction.

In some embodiments, each tile of the first set of tiles is offset froman adjacent tile of the first set of tiles in a second directiondifferent from the first direction. In some embodiments, each tile ofthe second set of tiles is offset from an adjacent tile of the secondset of tiles in the second direction.

In some embodiments, generating the first set of tiles includesgenerating the first layout design of the first set of memory cells. Insome embodiments, generating the second set of tiles includes generatingthe second layout design of the second set of memory cells.

In some embodiments, each tile of the first set of tiles and each tileof the second set of tiles extends in a third direction different fromthe first direction and the second direction.

FIG. 1 is a circuit diagram of a memory cell 100, in accordance withsome embodiments.

Memory cell 100 is a five transistor (5T) single port (SP) static randomaccess memory (SRAM) memory cell used for illustration. In someembodiments, memory cell 100 employs a number of transistors other thanfive. Other types of memory are within the scope of various embodiments.

Memory cell 100 comprises three P-type metal oxide semiconductor (PMOS)transistors P1, P2 and P3, and two N-type metal oxide semiconductor(NMOS) transistors N1 and N2. Transistors P1, P2, N1, and N2 form across-latch or a pair of cross-coupled inverters. For example, PMOStransistor P1 and NMOS transistor N1 form a first inverter while PMOStransistor P2 and NMOS transistor N2 form a second inverter.

A source terminal of each of PMOS transistors P1 and P2 are configuredas a voltage supply node NODE_1. Each voltage supply node NODE_1 iscoupled to a first voltage source VDDI. A drain terminal of PMOStransistor P1 is coupled with a drain terminal of NMOS transistor N1, agate terminal of PMOS transistor P2, a gate terminal of NMOS transistorN2, and is configured as a storage node NDB.

A drain terminal of PMOS transistor P2 is coupled with a drain terminalof NMOS transistor N2, a gate terminal of PMOS transistor P1, a gateterminal of NMOS transistor N1, a source terminal of PMOS transistor P3,and is configured as a storage node ND. A source terminal of each ofNMOS transistors N1 and N2 is configured as a supply reference voltagenode (not labelled) having a supply reference voltage VSS. The sourceterminal of each of NMOS transistors N1 and N2 is also coupled to supplyreference voltage VSS.

A word line WL1 is coupled with a gate terminal of PMOS transistor P3.Word line WL1 is also called a write control line because PMOStransistor P3 is configured to be controlled by a signal on word lineWL1 in order to transfer data between bit line BL1 and node ND.

A drain terminal of PMOS transistor P3 is coupled to a bit line BL1. Bitline BL1 is configured as both data input and output for memory cell100. In some embodiments, in a write operation, applying a logical valueto a bit line BL1 enables writing the logical value on the bit line BL1to memory cell 100. Bit line BL1 is called a data line because the datacarried on bit line BL1 is written to and read from node ND. In someembodiments, the source terminal of PMOS transistor P3 is coupled to thebit line BL1, and the drain terminal of PMOS transistor P3 is coupled tothe storage node ND.

FIG. 2A is a block diagram of a memory cell array 200A having aplurality of memory cells in FIG. 1, in accordance with someembodiments. For example, memory cell 100 of FIG. 1 is usable as one ormore memory cells in memory cell array 200A.

Memory cell array 200A comprises an array of memory cells 202[1,1],202[1,2], . . . , 202[2,2], . . . , 202[M,N] (collectively referred toas “array of memory cells 202A”) having M rows and N columns, where N isa positive integer corresponding to the number of columns in array ofmemory cells 202A and M is a positive integer corresponding to thenumber of rows in array of memory cells 202A. The rows of cells in arrayof memory cells 202A are arranged in a first direction X. The columns ofcells in array of memory cells 202A are arranged in a second directionY. The second direction Y is different from the first direction X. Insome embodiments, the second direction Y is perpendicular to the firstdirection X. Memory cell 100 of FIG. 1 is usable as one or more memorycells in array of memory cells 202A.

Memory cell array 200A further includes 2N bit lines BL[1], . . . BL[2N](collectively referred to as “bit line BL”). Each column 1, . . . , N inarray of memory cells 202A is overlapped by a pair of bit lines BL[1], .. . , BL[2N]. Each bit line BL extends in the second direction Y and isover a column of cells (e.g., column 1, . . . , N). In some embodiments,memory cell array 200A does not include one or more bit line bars BLB.Note that the term “bar” as used in this context indicates a logicallyinverted signal, for example, bit line bar BLB[1], . . . BLB[N] carriesa signal logically inverted from a signal carried by bit line BL[1], . .. BL[N].

A bit line of the set of bit lines BL in array of memory cells 202A orarray of memory cells 202B of FIG. 2B corresponds to bit line BL1 ofFIG. 1.

In some embodiments, a pair of memory cells of array of memory cells202A are positioned between a pair of bit lines of bit lines BL. Forexample, in row 1 and column 1 of memory cell array 200A, memory cell202[1,1] and memory cell 202[1,2] are each positioned between bit lineBL[1] and BL[2]. Similarly, in row 1 and column 2 of memory cell array200A, memory cell 202[1,3] and memory cell 202[1,4] are each positionedbetween bit line BL[3] and BL[4].

Memory cell array 200A further includes 2M word lines WL[1], . . .WL[2M] (collectively referred to as “word line WL”). Each word line WLextends in the first direction X and is over a row of cells (e.g., row1, . . . , M). Each row 1, . . . , M in array of memory cells 202A isoverlapped by a pair of word lines WL[1], . . . , WL[2M]. For example,word line WL[1] and WL[2] each overlap row 1 of array of memory cells202A. Similarly, word line WL[3] and WL[4] each overlap row 2 of arrayof memory cells 202A and word line WL[7] and WL[2M] each overlap row Mof array of memory cells 202A.

A word line of the set of word lines WL in array of memory cells 202A orarray of memory cells 202B of FIG. 2B corresponds to word line WL1 ofFIG. 1.

In some embodiments, each row of memory cells of array of memory cells202A are positioned between a pair of word lines of word lines WL. Forexample, in row 1 of memory cell array 200A, memory cells 202[1,1],202[1,2], . . . , 202[1,N] are positioned between word line WL[1] andWL[2]. Similarly, in row 2 of memory cell array 200A, memory cells202[2,1], 202[2,2], . . . , 202[2,N] are positioned between word lineWL[3] and WL[4].

Each memory cell in the array of memory cells 202A is coupled to acorresponding bit line of bit lines BL and a corresponding word line ofword lines WL. For example, memory cell 202[1,1] is coupled to bit lineBL[1] and word line WL[1]. Similarly, memory cell 202[1,2] is coupled tobit line BL[2] and word line WL[2], memory cell 202[1,3] is coupled tobit line BL[3] and word line WL[2], memory cell 202[2,1] is coupled tobit line BL[1] and word line WL[4], and memory cell 202[2,2] is coupledto bit line BL[2] and word line WL[3].

Memory cells of the array of memory cells 202A are grouped into a firstset of memory cells 204 and a second set of memory cells 206.

The first set of memory cells 204 includes memory cells 204 a, 204 b, .. . , 204 i.

The second set of memory cells 206 includes memory cells 206 a, 206 b,206 c and 206 d.

In some embodiments, the memory cells of the first set of memory cells204 correspond to memory cells of a first layout design type (e.g.,layout designs 300A-300B of FIGS. 3A-3B), and the second set of memorycells 206 correspond to memory cells of a second layout design type(e.g., layout designs 400A-400B of FIGS. 4A-4B) different from the firstlayout design type.

In some embodiments, the memory cells of the first set of memory cells204 correspond to memory cells of the second layout design type (e.g.,layout designs 400A-400B of FIGS. 4A-4B), and the second set of memorycells 206 correspond to memory cells of the first layout design type(e.g., layout designs 300A-300B of FIGS. 3A-3B).

FIG. 2B is a circuit diagram of a memory cell array 200B having aplurality of memory cells in FIG. 1, in accordance with someembodiments. Memory cell array 200B is an embodiment of the blockdiagram of memory cell array 200A of FIG. 2A expressed in a circuitdiagram. Memory cell 100 of FIG. 1 is usable as one or more memory cellsin memory cell array 200B.

In comparison with memory cell array 200A of FIG. 2A, array of memorycells 202B of memory cell array 200B replace array of memory cells 202Aof FIG. 2A. Array of memory cells 202B is an embodiment of the array ofmemory cells 202A of FIG. 2A.

Each memory cell in the array of memory cells 202B comprises acorresponding PMOS transistor P3[1,1], P3[1,2] . . . , P[M,N] of a setof PMOS transistors 210 (not labelled) coupled to each of acorresponding inverter I1[1,1], I1[1,2], . . . , I1[M,N] of a first setof inverters 212 (not labelled) and a corresponding inverter I2[1,1],I2[1,2], . . . , I2[M,N] of a second set of inverters 214 (notlabelled). The first set of inverters 212 and the second set ofinverters 214 are part of a set of cross-coupled inverters 216 (notlabelled).

One or more of PMOS transistors P3[1,1], P3[1,2], . . . , P3[M,N] of theset of PMOS transistors 210 in array of memory cells 202B corresponds toPMOS transistor P3 of FIG. 1.

One or more of inverters I1[1,1], I1[1,2], . . . , I1[M,N] of the firstset of inverters 212 in array of memory cells 202B corresponds to PMOStransistor P2 and NMOS transistor N2 of FIG. 1.

One or more of inverters I2[1,1], I2[1,2], . . . , I2[M,N] of the secondset of inverters 214 in array of memory cells 202B corresponds to PMOStransistor P1 and NMOS transistor N1 of FIG. 1.

In some embodiments, one or more memory cells of memory cell array 200Aor 200B includes one or more single port (SP) SRAM cells. In someembodiments, one or more memory cells of memory cell array 200A or 200Bincludes one or more dual port (DP) SRAM cells. Different types ofmemory cells in memory cell array 200A or 200B are within thecontemplated scope of the present disclosure. Different configurationsof array of memory cells 202A or 202B are within the contemplated scopeof the present disclosure. Different configurations of bit lines BL orword lines WL in array of memory cells 202A or 202B are within thecontemplated scope of the present disclosure.

In some embodiments, memory cell array 200A-200B includes an array of 5TSRAM cells (FIG. 1) causing memory cell array 200A-200B to include lesstransistors than other memory cell arrays. In some embodiments, bymemory cell array 200A-200B including less transistors, memory cellarray 200A-200B occupies less area than other memory cell arrays. Insome embodiments, by occupying less area than other memory cell arrays,memory cell array 200A-200B is denser and has a larger memory capacitycompared with other approaches.

FIG. 3A is a diagram of a layout design 300A, in accordance with someembodiments. Layout design 300A corresponds to a layout diagram of aportion of memory cell array 200A-200B of FIGS. 2A-2B. For example,layout design 300A corresponds to a layout design of one or more memorycells 206 a, 206 b, 206 c or 206 d of the second set of memory cells 206of FIGS. 2A-2B.

Components that are the same or similar to those in one or more of FIGS.3B, 4A-4B and 6-8 (shown below) are given the same reference numbers,and detailed description thereof is thus omitted.

Structural relationships including alignment, lengths and widths, aswell as configurations of layout design 400A-400B (FIGS. 4A-4B), layoutdesign 600 (FIG. 6), layout design 700 (FIG. 7) or layout design 800(FIG. 8) are similar to the structural relationships and configurationsof layout design 300A or 300B of FIGS. 3A-3B, and will not be describedin FIGS. 4A-4B, and 6-8 for brevity.

Layout design 300A is usable to manufacture integrated circuit 500A(FIGS. 5A-5H).

Layout design 300A corresponds to a layout design of memory cells202[1,2], 202[1,3], 202[2,2] and 202[2,3] of FIGS. 2A-2B. In someembodiments, layout design 300A corresponds to a layout design of memorycells 202[1,6], 202[1,7], 202[2,6] and 202[2,7] of FIGS. 2A-2B. In someembodiments, layout design 300A corresponds to a layout design of memorycells 202[3,2], 202[3,3], 202[4,2] and 202[4,3] of FIGS. 2A-2B. In someembodiments, layout design 300A corresponds to a layout design of memorycells 202[3,6], 202[3,7], 202[4,6] and 202[4,7] of FIGS. 2A-2B. In someembodiments, layout design 300A corresponds to a layout design of one ormore memory cells 204 a, 204 b, . . . , 204 i of the first set of memorycells 204 of FIGS. 2A-2B.

Layout design 300A includes a first portion 302 a, a second portion 302b, a third portion 302 c and a fourth portion 302 d. A center of layoutdesign 300A corresponds to a boundary between each of the first portion302 a, second portion 302 b, third portion 302 c and fourth portion 302d. In some embodiments, the first portion 302 a corresponds to thelayout design of memory cell 202[1,2], the second portion 302 bcorresponds to the layout design of memory cell 202[2,2], the thirdportion 302 c corresponds to the layout design of memory cell 202[1,3],and the fourth portion 302 d corresponds to the layout design of memorycell 202[2,3]. First portion 302 a, second portion 302 b, third portion302 c and fourth portion 302 d have corresponding corner notches 390 a,390 b, 390 c and 390 d (see FIG. 3B). Other configurations of the firstportion 302 a, second portion 302 b, third portion 302 c and fourthportion 302 d are within the scope of the present disclosure.

The first portion 302 a includes active region layout patterns 304 a,306 a, 308 a and 310 a (collectively referred to as “set of activeregion layout patterns 312 a”). Active region layout patterns 304 a, 306a, 308 a and 310 a are useable to manufacture corresponding activeregions 504 a 1, 506 a 1, 508 a 1, and 510 a 1 of integrated circuit500A or 500B (FIGS. 5A-5H).

In some embodiments, the set of active region layout patterns 312 a isreferred to as an oxide definition (OD) layout pattern which definessource or drain diffusion layout patterns of layout design 300A-300B.For example, in some embodiments, active region layout pattern 304 a isuseable to manufacture the drain and source regions of a PMOS transistorP1 a of FIGS. 3A-3B, active region layout pattern 306 a is useable tomanufacture the drain and source regions of an NMOS transistor N1 a ofFIGS. 3A-3B, active region layout pattern 308 a is useable tomanufacture the drain and source regions of an NMOS transistor N2 a ofFIGS. 3A-3B, and active region layout pattern 310 a is useable tomanufacture the drain and source regions of PMOS transistors P2 a andPG1 a of FIGS. 3A-3B. In some embodiments, PMOS transistor P1 acorresponds to PMOS transistor P1 (FIG. 1), PMOS transistor P2 acorresponds to PMOS transistor P2 (FIG. 1), PMOS transistor PG1 acorresponds to PMOS transistor P3 (FIG. 1), NMOS transistor N1 acorresponds to NMOS transistor N1 (FIG. 1), and NMOS transistor N2 acorresponds to NMOS transistor N2 (FIG. 1).

Each of the layout patterns of the set of active region layout patterns312 a is separated from an adjacent layout pattern of the set of activeregion layout patterns 312 a in a first direction X by a first pitch(not labelled). In some embodiments, an adjacent element is directlynext to another element. Each of the layout patterns of the set ofactive region layout patterns 312 a extend in a second direction Ydifferent from the first direction X and is located on a first layoutlevel. In some embodiments, the first layout level corresponds to theactive region of layout design 300A-300B or 400A-400B (FIGS. 4A-4B).

Active region layout pattern 304 a is adjacent or directly next to afirst side of the first portion 302 a of layout design 300A and a cornernotch 390 a. Active region layout pattern 310 a is adjacent or directlynext to a second side of the first portion 302 a of layout design 300A.The second side of the first portion 302 a of layout design 300A isopposite from the first side of the first portion 302 a of layout design300A. In some embodiments, active region layout pattern 306 a isadjacent to corner notch 390 a. In some embodiments, the active regionlayout pattern 304 a extends from a side of layout design 300A to thecorner notch 390 a of the layout design. In some embodiments, the activeregion layout pattern 304 a and 304 b extends from notch 390 a to notch390 b. In some embodiments, the active region layout pattern 304 bextends from the side of layout design 300A to the corner notch 390 b ofthe layout design. In some embodiments, the active region layout pattern304 c extends from a side of layout design 300A to the corner notch 390c of the layout design. In some embodiments, the active region layoutpattern 304 c and 304 d extends from notch 390 c to notch 390 d. In someembodiments, the active region layout pattern 304 d extends from theside of layout design 300A to the corner notch 390 d of the layoutdesign.

In some embodiments, a length of active region layout pattern 304 a inthe second direction Y is different from a length of active regionlayout pattern 310 a in the second direction Y. In some embodiments, alength of active region layout pattern 306 a in the second direction Yis different from a length of active region layout pattern 308 a in thesecond direction Y. In some embodiments, a length of active regionlayout pattern 306 a in the second direction Y is the same as the lengthof active region layout pattern 308 a in the second direction Y. Otherquantities or configurations of the set of active region layout patterns312 a are within the scope of the present disclosure.

The first portion 302 a further includes gate layout patterns 320 a, 322a and 324 a (collectively referred to as “set of gate layout patterns326 a”). In some embodiments, gate layout patterns 320 a, 322 a and 324a are usable to manufacture corresponding gate structures 520 a, 522 aand 524 a of integrated circuit 500A-500B (FIGS. 5A-5H). In someembodiments, gate layout pattern 320 a is useable to manufacture gateregions of PMOS transistor P1 a and NMOS transistor N1 a, gate layoutpattern 322 a is useable to manufacture gate regions of NMOS transistorN2 a and PMOS transistor P2 a, and gate layout pattern 324 a is useableto manufacture a gate region of PMOS transistor PG1 a. In someembodiments, gate layout pattern 322 a is adjacent to corner notch 390a.

In some embodiments, each gate layout pattern of the set of gate layoutpatterns 326 a extends in the first direction X and overlaps the set ofactive region layout patterns 312 a. The set of gate layout patterns 326a is positioned on a second layout level different from the first layoutlevel. In some embodiments, the second layout level corresponds to thePOLY level of layout design 300A-300B or 400A-400B (FIGS. 4A-4B). Theset of active region layout patterns 312 a is below the set of gatelayout patterns 326 a. Other quantities or configurations of the set ofgate layout patterns 326 a are within the scope of the presentdisclosure.

The first portion 302 a further includes conductive feature layoutpatterns 330 a, 332 a, 334 a and 336 a (collectively referred to as “setof conductive feature layout patterns 338 a”). In some embodiments,conductive feature layout patterns 330 a, 332 a, 334 a and 336 a areusable to manufacture corresponding conductive structures 530 a, 532 a,534 a and 536 a of integrated circuit 500A-500B (FIGS. 5A-5H).

In some embodiments, the set of conductive feature layout patterns 338 aextends in the first direction X, and is over at least the set of activeregion layout patterns 312 a or the set of gate layout patterns 326 a.Conductive feature layout pattern 330 a overlaps active region layoutpatterns 304 a and 306 a. Conductive feature layout pattern 334 aoverlaps active region layout patterns 308 a and 310 a. Conductivefeature layout patterns 332 a, 336 a are over corresponding activeregion layout patterns 308 a, 310 a. In some embodiments, conductivefeature layout pattern 330 a is adjacent to corner notch 390 a.

In some embodiments, each conductive feature layout pattern of the setof conductive feature layout patterns 338 a is separated from anadjacent layout pattern of the set of conductive feature layout patterns338 a in at least the first direction X or the second direction Y. Theset of conductive feature layout patterns 338 a is on a third layoutlevel different from the first layout level and the second layout level.In some embodiments, the third layout level corresponds to the metal one(M1) level of layout design 300A-300B or 400A-400B (FIGS. 4A-4B). Otherquantities or configurations of the set of conductive feature layoutpatterns 338 a are within the scope of the present disclosure.

The first portion 302 a further includes via layout patterns 360 a, 362a, 364 a, 366 a, 368 a, 370 a (collectively referred to as “set of vialayout patterns 358 a”). In some embodiments, via layout patterns 360 a,362 a, 364 a, 366 a, 368 a, 370 a are usable to manufacturecorresponding vias 560 a, 562 a, 564 a, 566 a, 568 a, 570 a ofintegrated circuit 500A-500B (FIGS. 5A-5H).

In some embodiments, each via layout pattern of the set of via layoutpatterns 358 a is located where each conductive feature layout patternof the set of conductive feature layout patterns 338 a overlaps eachactive region layout pattern of the set of active region layout patterns312 a. The set of via layout patterns 358 a are between the set ofconductive feature layout patterns 338 a and the set of active regionlayout patterns 312 a. In some embodiments, the set of via layoutpatterns 358 a are on at least the via zero (V0) level of layout design300A-300B or 400A-400B (FIGS. 4A-4B). In some embodiments, the V0 levelis between the third layout level and the first or second layout levelof layout design 300A-300B or 400A-400B (FIGS. 4A-4B). In someembodiments, the first portion 302 a of layout design 300A is usable tofabricate memory cell 202[1,2], 202[1,6], 202[3,2] or 202[3,6] of thesecond set of memory cells 206 of memory cell array 200A or 200B. Otherquantities or configurations of the set of via layout patterns 358 a arewithin the scope of the present disclosure.

The second portion 302 b includes active region layout patterns 304 b,306 b, 308 b and 310 b (collectively referred to as “set of activeregion layout patterns 312 b”), gate layout patterns 320 b, 322 b and324 b (collectively referred to as “set of gate layout patterns 326 b”),conductive feature layout patterns 330 b, 332 b, 334 b and 336 b(collectively referred to as “set of conductive feature layout patterns338 b”) and via layout patterns 360 b, 362 b, 364 b, 366 b, 368 b, 370 b(collectively referred to as “set of via layout patterns 358 b”).

In some embodiments, the first portion 302 a and the second portion 302b of layout design 300A-300B are mirror images of each other withrespect to the second direction Y, and similar detailed description istherefore omitted.

In some embodiments, active region layout patterns 304 b, 306 b, 308 band 310 b are useable to manufacture active regions similar tocorresponding active regions 504 a 1, 506 a 1, 508 a 1, and 510 a 1 ofintegrated circuit 500A or 500B (FIGS. 5A-5H). In some embodiments, gatelayout patterns 320 b, 322 b and 324 b are usable to manufacture gatestructures similar to corresponding gate structures 520 a, 522 a and 524a of integrated circuit 500A-500B (FIGS. 5A-5H). In some embodiments,conductive feature layout patterns 330 b, 332 b, 334 b and 336 b areusable to manufacture conductive structures similar to correspondingconductive structures 530 a, 532 a, 534 a and 536 a of integratedcircuit 500A-500B (FIGS. 5A-5H). In some embodiments, via layoutpatterns 360 b, 362 b, 364 b, 366 b, 368 b, 370 b are usable tomanufacture vias similar to corresponding vias 560 a, 562 a, 564 a, 566a, 568 a, 570 a of integrated circuit 500A-500B (FIGS. 5A-5H).

In some embodiments, active region layout patterns 304 a and 304 b arepart of a same continuous active region layout pattern. In someembodiments, active region layout patterns 308 a and 308 b are part of asame continuous active region layout pattern. In some embodiments,active region layout patterns 310 a and 310 b are part of a samecontinuous active region layout pattern.

In some embodiments, the second portion 302 b of layout design 300A isusable to fabricate memory cell 202[2,2], 202[2,6], 202[M,2] or 202[M,6]of the second set of memory cells 206 of memory cell array 200A or 200B.

The third portion 302 c includes active region layout patterns 304 c,306 c, 308 c and 310 c (collectively referred to as “set of activeregion layout patterns 312 c”), gate layout patterns 320 c, 322 c and324 c (collectively referred to as “set of gate layout patterns 326 c”),conductive feature layout patterns 330 c, 332 c, 334 c and 336 c(collectively referred to as “set of conductive feature layout patterns338 c”) and via layout patterns 360 c, 362 c, 364 c, 366 c, 368 c, 370 c(collectively referred to as “set of via layout patterns 358 c”).

In some embodiments, the first portion 302 a and the third portion 302 cof layout design 300A-300B are mirror images of each other with respectto the first direction X, and similar detailed description is thereforeomitted.

In some embodiments, active region layout patterns 304 c, 306 c, 308 cand 310 c are useable to manufacture active regions similar tocorresponding active regions 504 a 1, 506 a 1, 508 a 1, and 510 a 1 ofintegrated circuit 500A or 500B (FIGS. 5A-5H). In some embodiments, gatelayout patterns 320 c, 322 c and 324 c are usable to manufacture gatestructures similar to corresponding gate structures 520 a, 522 a and 524a of integrated circuit 500A-500B (FIGS. 5A-5H). In some embodiments,conductive feature layout patterns 330 c, 332 c, 334 c and 336 c areusable to manufacture conductive structures similar to correspondingconductive structures 530 a, 532 a, 534 a and 536 a of integratedcircuit 500A-500B (FIGS. 5A-5H). In some embodiments, via layoutpatterns 360 c, 362 c, 364 c, 366 c, 368 c, 370 c are usable tomanufacture vias similar to corresponding vias 560 a, 562 a, 564 a, 566a, 568 a, 570 a of integrated circuit 500A-500B (FIGS. 5A-5H). In someembodiments, gate layout patterns 324 a and 324 c are part of a samecontinuous gate layout pattern.

In some embodiments, the third portion 302 c of layout design 300A isusable to fabricate memory cell 202[1,3], 202[1,7], 202[3,3] or 202[3,7]of the second set of memory cells 206 of memory cell array 200A or 200B.

The fourth portion 302 d includes active region layout patterns 304 d,306 d, 308 d and 310 d (collectively referred to as “set of activeregion layout patterns 312 d”), gate layout patterns 320 d, 322 d and324 d (collectively referred to as “set of gate layout patterns 326 d”),conductive feature layout patterns 330 d, 332 d, 334 d and 336 d(collectively referred to as “set of conductive feature layout patterns338 d”) and via layout patterns 360 d, 362 d, 364 d, 366 d, 368 d, 370 d(collectively referred to as “set of via layout patterns 358 d”).

In some embodiments, the third portion 302 c and the fourth portion 302d of layout design 300A-300B are mirror images of each other withrespect to the second direction Y, and similar detailed description istherefore omitted. In some embodiments, the second portion 302 b and thefourth portion 302 d of layout design 300A-300B are mirror images ofeach other with respect to the first direction X, and similar detaileddescription is therefore omitted.

In some embodiments, active region layout patterns 304 d, 306 d, 308 dand 310 d are useable to manufacture active regions similar tocorresponding active regions 504 a 1, 506 a 1, 508 a 1, and 510 a 1 ofintegrated circuit 500A or 500B (FIGS. 5A-5H). In some embodiments,active region layout patterns 304 b, 304 c and 304 d are useable tomanufacture the drain and source regions of corresponding PMOStransistors P1 b, P1 c and P1 d, active region layout patterns 306 b,306 c and 306 d are useable to manufacture the drain and source regionsof corresponding NMOS transistors N1 b, N1 c and N1 d, active regionlayout patterns 308 b, 308 c and 308 d are useable to manufacture thedrain and source regions of corresponding NMOS transistors N2 b, N2 cand N2 d, active region layout pattern 310 b is useable to manufacturethe drain and source regions of PMOS transistors P2 b and PG1 b, activeregion layout pattern 310 c is useable to manufacture the drain andsource regions of PMOS transistors P2 c and PG1 c, and active regionlayout pattern 310 d is useable to manufacture the drain and sourceregions of PMOS transistors P2 d and PG1 d.

In some embodiments, PMOS transistor P1 b, P1 c or P1 d is similar toPMOS transistor P1 (FIG. 1), PMOS transistor P2 b, P2 c or P2 d issimilar to PMOS transistor P2 (FIG. 1), PMOS transistor PG1 b, PG1 c orPG1 d is similar to PMOS transistor P3 (FIG. 1), NMOS transistor N1 b,N1 c or N1 d is similar to NMOS transistor N1 (FIG. 1), and NMOStransistor N2 b, N2 c or N2 d is similar to NMOS transistor N2 (FIG. 1).

In some embodiments, gate layout patterns 320 d, 322 d and 324 d areusable to manufacture gate structures similar to corresponding gatestructures 520 a, 522 a and 524 a of integrated circuit 500A-500B (FIGS.5A-5H). In some embodiments, gate layout pattern 320 b is useable tomanufacture gate regions of PMOS transistor P1 b and NMOS transistor N1b, gate layout pattern 322 b is useable to manufacture gate regions ofNMOS transistor N2 b and PMOS transistor P2 b, gate layout pattern 320 cis useable to manufacture gate regions of PMOS transistor P1 c and NMOStransistor N1 c, gate layout pattern 322 c is useable to manufacturegate regions of NMOS transistor N2 c and PMOS transistor P2 c, gatelayout pattern 320 d is useable to manufacture gate regions of PMOStransistor P1 d and NMOS transistor N1 d, gate layout pattern 322 d isuseable to manufacture gate regions of NMOS transistor N2 d and PMOStransistor P2 d, and gate layout patterns 324 b, 324 c and 324 d areuseable to manufacture corresponding gate regions of PMOS transistorsPG1 b, PG1 c and PG1 d.

In some embodiments, conductive feature layout patterns 330 d, 332 d,334 d and 336 d are usable to manufacture conductive structures similarto corresponding conductive structures 530 a, 532 a, 534 a and 536 a ofintegrated circuit 500A-500B (FIGS. 5A-5H). In some embodiments, vialayout patterns 360 d, 362 d, 364 d, 366 d, 368 d, 370 d are usable tomanufacture vias similar to corresponding vias 560 a, 562 a, 564 a, 566a, 568 a, 570 a of integrated circuit 500A-500B (FIGS. 5A-5H).

In some embodiments, active region layout patterns 304 c and 304 d arepart of a same continuous active region layout pattern. In someembodiments, active region layout patterns 308 c and 308 d are part of asame continuous active region layout pattern. In some embodiments,active region layout patterns 310 c and 310 d are part of a samecontinuous active region layout pattern.

Each of the set of active region layout patterns 312 b, 312 c and 312 dis similar to the set of active region layout patterns 312 a, andsimilar detailed description is therefore omitted. Each of the set ofgate layout patterns 326 b, 326 c and 326 d is similar to the set ofgate layout patterns 326 a, and similar detailed description istherefore omitted. Each of the set of conductive feature layout patterns338 b, 338 c and 338 d is similar to the set of conductive featurelayout patterns 338 a, and similar detailed description is thereforeomitted. Each of the set of via layout patterns 358 b, 358 c and 358 dis similar to the set of via layout patterns 358 a, and similar detaileddescription is therefore omitted. In some embodiments, gate layoutpatterns 324 b and 324 d are part of a same continuous gate layoutpattern.

In some embodiments, the fourth portion 302 d of layout design 300A isusable to fabricate memory cell 202[2,3], 202[2,7], 202[M,3] or 202[M,7]of the second set of memory cells 206 of memory cell array 200A or 200B.

Other quantities or configurations of the set of active region layoutpatterns 312 b, 312 c, 312 d, the set of gate layout patterns 326 b, 326c, 326 d, the set of conductive feature layout patterns 338 b, 338 c,338 d, or the set of via layout patterns 358 b, 358 c and 358 d arewithin the scope of the present disclosure.

Layout design 300A further includes conductive feature layout patterns340 a, 340 b (collectively referred to as “set of conductive featurelayout patterns 340”). In some embodiments, conductive feature layoutpatterns 340 a and 340 b are usable to manufacture conductive structure540 a or similar conductive structures of integrated circuit 500A-500B(FIGS. 5A-5H).

In some embodiments, the set of conductive feature layout patterns 340extends in the first direction X, and is over gate layout patterns 324 aand 324 b. Conductive feature layout pattern 340 a is over gate layoutpattern 324 a. Conductive feature layout pattern 340 b is over gatelayout pattern 324 b.

In some embodiments, each conductive feature layout pattern of the setof conductive feature layout patterns 340 is separated from an adjacentlayout pattern of the set of conductive feature layout patterns 340 inat least the second direction Y. The set of conductive feature layoutpatterns 340 is on the third layout level.

Layout design 300A further includes conductive feature layout patterns342 a, 342 b (collectively referred to as “set of conductive featurelayout patterns 342”). In some embodiments, conductive feature layoutpatterns 342 a and 342 b are usable to manufacture correspondingconductive structures 542 a and 542 b of integrated circuit 500A-500B(FIGS. 5A-5H). In some embodiments, the set of conductive feature layoutpatterns 342 extends in the first direction X. Conductive feature layoutpattern 342 a is over active region layout patterns 304 a and 304 b.Conductive feature layout pattern 342 b is over active region layoutpatterns 306 a and 306 b. In some embodiments, each conductive featurelayout pattern of the set of conductive feature layout patterns 342 isseparated from an adjacent layout pattern of the set of conductivefeature layout patterns 342 in at least the first direction X. The setof conductive feature layout patterns 342 is on the third layout level.

Layout design 300A further includes conductive feature layout patterns344 a, 344 b (collectively referred to as “set of conductive featurelayout patterns 344”). In some embodiments, conductive feature layoutpatterns 344 a and 344 b are usable to manufacture conductive structuressimilar to corresponding conductive structures 542 a and 542 b ofintegrated circuit 500A-500B (FIGS. 5A-5H). In some embodiments, the setof conductive feature layout patterns 344 extends in the first directionX. Conductive feature layout pattern 344 a is over active region layoutpatterns 304 c and 304 d. Conductive feature layout pattern 344 b isover active region layout patterns 306 c and 306 d. In some embodiments,each conductive feature layout pattern of the set of conductive featurelayout patterns 344 is separated from an adjacent layout pattern of theset of conductive feature layout patterns 344 in at least the firstdirection X. The set of conductive feature layout patterns 344 is on thethird layout level.

Layout design 300A further includes at least conductive feature layoutpattern 350 a (collectively referred to as “set of conductive featurelayout patterns 350”). In some embodiments, conductive feature layoutpattern 350 a is usable to manufacture conductive structure 550 a ofintegrated circuit 500A-500B (FIGS. 5A-5H).

In some embodiments, conductive feature layout pattern 350 a extends inthe first direction X, and is over at least active region layoutpatterns 310 a, 310 b, 310 c and 310 d.

In some embodiments, each conductive feature layout pattern 350 a of theset of conductive feature layout patterns (not labelled) is separatedfrom an adjacent layout pattern of the set of conductive feature layoutpatterns (not labelled) in at least the first direction X or the seconddirection Y. The conductive feature layout pattern 350 a is on a fourthlayout level different from the first layout level, the second layoutlevel and the third layout level. In some embodiments, the fourth layoutlevel corresponds to the metal two (M2) level of layout design 300A-300Bor 400A-400B (FIGS. 4A-4B).

Layout design 300A further includes via layout patterns 374 a, 374 b(collectively referred to as “set of via layout patterns 374”). In someembodiments, via layout patterns 374 a, 374 b are usable to manufacturecorresponding vias 574 a, 574 b of integrated circuit 500A-500B (FIGS.5A-5H). In some embodiments, each via layout pattern of the set of vialayout patterns 374 is located where conductive feature layout pattern342 a overlaps active region layout patterns 304 a and 304 b, or whereconductive feature layout pattern 342 b overlaps active region layoutpatterns 306 a and 306 b. Via layout pattern 374 a is between conductivefeature layout pattern 342 a and active region layout patterns 304 a and304 b. Via layout pattern 374 b is between conductive feature layoutpattern 342 b and active region layout patterns 306 a and 306 b. In someembodiments, the set of via layout patterns 374 are on at least the V0level of layout design 300A-300B or 400A-400B (FIGS. 4A-4B).

Layout design 300A further includes via layout patterns 376 a, 376 b(collectively referred to as “set of via layout patterns 376”). In someembodiments, via layout patterns 376 a, 376 b are usable to manufacturevias similar to corresponding vias 574 a, 574 b of integrated circuit500A-500B (FIGS. 5A-5H). In some embodiments, each via layout pattern ofthe set of via layout patterns 376 is located where conductive featurelayout pattern 344 a overlaps active region layout patterns 304 c and304 d, or where conductive feature layout pattern 344 b overlaps activeregion layout patterns 306 c and 306 d. Via layout pattern 376 a isbetween conductive feature layout pattern 344 a and active region layoutpatterns 304 c and 304 d. Via layout pattern 376 b is between conductivefeature layout pattern 344 b and active region layout patterns 306 c and306 d. In some embodiments, the set of via layout patterns 376 are on atleast the V0 level of layout design 300A-300B or 400A-400B (FIGS.4A-4B).

Layout design 300A further includes via layout patterns 378 a, 378 b(collectively referred to as “set of via layout patterns 378”). In someembodiments, via layout patterns 378 a, 378 b are usable to manufacturevia 578 a or similar to via 578 a of integrated circuit 500A-500B (FIGS.5A-5H). In some embodiments, the set of via layout patterns 378 islocated where conductive feature layout pattern 350 a overlaps activeregion layout patterns 310 a, 310 b, 310 c and 310 d. Via layout pattern378 a is between conductive feature layout pattern 350 a and activeregion layout patterns 310 a and 310 b. Via layout pattern 378 b isbetween conductive feature layout pattern 350 a and active region layoutpatterns 310 c and 310 d. In some embodiments, the set of via layoutpatterns 378 are on at least the via one (V1) level of layout design300A-300B or 400A-400B (FIGS. 4A-4B). In some embodiments, the V1 levelis between the third layout level and the fourth layout level of layoutdesign 300A-300B or 400A-400B (FIGS. 4A-4B).

Layout design 300A further includes via layout patterns 380 a, 380 b(collectively referred to as “set of via layout patterns 380”). In someembodiments, via layout patterns 380 a, 380 b are usable to manufacturevia 580 a or vias similar to via 580 a of integrated circuit 500A-500B(FIGS. 5A-5H). In some embodiments, via layout pattern 380 a is locatedwhere conductive feature layout pattern 340 a overlaps gate layoutpatterns 324 a and 324 c. In some embodiments, via layout pattern 380 bis located where conductive feature layout pattern 340 b overlaps gatelayout patterns 324 b and 324 d. Via layout pattern 380 a is betweenconductive feature layout pattern 340 a and gate layout patterns 324 aand 324 c. Via layout pattern 380 b is between conductive feature layoutpattern 340 b and gate layout patterns 324 b and 324 d. In someembodiments, the set of via layout patterns 380 are on at least the viaover gate (VG) level of layout design 300A-300B or 400A-400B (FIGS.4A-4B). In some embodiments, the VG level is between the third layoutlevel and the second layout level of layout design 300A-300B or400A-400B (FIGS. 4A-4B).

Other quantities or configurations of conductive feature layout patterns340 a, 340 b, 342 a, 342 b, 344 a, 344 b or 350 a, or via layoutpatterns 374 a, 374 b, 376 a, 376 b, 378 a, 378 b, 380 a or 380 b arewithin the scope of the present disclosure.

In some embodiments, layout design 300A-300B has a non-rectangular shapewhich results in a smaller standard cell than other designs. In someembodiments, by having a smaller standard cell, layout design 300A-300Bcan be utilized to manufacture integrated circuits that are smaller thanother integrated circuits.

FIG. 3B is a diagram of a layout design 300B, in accordance with someembodiments.

Layout design 300B is usable to manufacture integrated circuit 500A(FIGS. 5A-5H). Layout design 300B is a variation of layout design 300Aof FIG. 3A. In comparison with layout design 300A of FIG. 3A, layoutdesign 300B further includes a first well layout pattern 314 and asecond well layout pattern 316.

First well layout pattern 314 extends in the second direction Y, and islocated on a fifth layout level. First well layout pattern 314 isuseable to manufacture a first well 501 (e.g., at least portions 501 a,501 b) of integrated circuit 500A (FIGS. 5A-5H). In some embodiments,the fifth layout level is different from the first layout level, thesecond layout level, the third layout level and the fourth layout level.In some embodiments, the fifth layout level corresponds to the welllevel of layout design 300A-300B or 400A-400B (FIGS. 4A-4B). In someembodiments, a portion of the fifth layout level includes the firstlayout level. First well layout pattern 314 includes layout patterns 354a, 354 b and 354 c.

Layout pattern 354 a extends in the second direction Y and is belowactive region layout patterns 304 a and 304 b. Layout pattern 354 a isadjacent to a side 352 a of the first portion 302 a or the secondportion 302 b of layout design 300B, and corner notches 390 a and 390 b.Layout pattern 354 a is useable to manufacture portion 501 a of firstwell 501 of integrated circuit 500A (FIGS. 5A-5H). Layout pattern 354 ahas a width W1 (not labelled) in the first direction X.

Layout pattern 354 b extends in the second direction Y and is belowactive region layout patterns 310 a, 310 b, 310 c and 310 d. Layoutpattern 354 b is positioned over centerlines 352 b 1 and 352 b 2 oflayout design 300B. In some embodiments, a center of layout pattern 354b is aligned with the centerlines 352 b 1 and 352 b 2 of layout design300B. Layout pattern 354 b is useable to manufacture at least portion501 b of the first well 501 of integrated circuit 500A (FIGS. 5A-5H).Layout pattern 354 b has a width W2 (not labelled) in the firstdirection X.

Layout pattern 354 c extends in the second direction Y and is belowactive region layout patterns 304 c and 304 d. Layout pattern 354 c isadjacent to a side 352 c of the third portion 302 c or the fourthportion 302 d of layout design 300B, and corner notches 390 c and 390 d.Layout pattern 354 c is useable to manufacture a portion of first well501 similar to portion 501 a. Layout pattern 354 c has width W1 (notlabelled) in the first direction X.

Second well layout pattern 316 extends in the second direction Y, and islocated on the fifth layout level. Second well layout pattern 316 isuseable to manufacture a second well 501′ (e.g., at least portion 501 c)of integrated circuit 500A (FIGS. 5A-5H).

Second well layout pattern 316 includes layout patterns 356 a and 356 b.

Layout pattern 356 a extends in the second direction Y and is belowactive region layout patterns 306 a, 306 b, 308 a and 308 b. Layoutpattern 356 a is between layout patterns 354 a and 354 b. Layout pattern356 a is useable to manufacture portion 501 c of second well 501′ ofintegrated circuit 500A (FIGS. 5A-5H). Layout pattern 356 a has a widthW3 (not labelled) in the first direction X.

Layout pattern 356 b extends in the second direction Y and is belowactive region layout patterns 306 c, 306 d, 308 c and 308 d. Layoutpattern 356 b is between layout patterns 354 b and 354 c. Layout pattern356 b is useable to manufacture a portion of second well 501′ similar toportion 501 c of integrated circuit 500A (FIGS. 5A-5H). Layout pattern356 b has width W3 (not labelled) in the first direction X.

In some embodiments, width W1, W2 or W3 is the same as another width ofwidth W1, W2 or W3. In some embodiments, width W1, W2 or W3 is differentfrom another width of width W1, W2 or W3.

Other configurations or quantities of first well layout pattern 314 orsecond well layout pattern 316 are within the scope of the presentdisclosure. Other configurations or quantities of layout patterns 354 a,354 b, 354 c, 356 a or 356 b are within the scope of the presentdisclosure.

FIG. 4A is a diagram of a layout design 400A, in accordance with someembodiments. Layout design 400A corresponds to a layout diagram of aportion of memory cell array 200A-200B of FIGS. 2A-2B. For example,layout design 400A corresponds to a layout design of one or more memorycells 204 a, 204 b, . . . , 204 i of the first set of memory cells 204of FIGS. 2A-2B.

Layout design 400A is similar to layout design 300A (FIG. 3A). Similarelements have a same reference number increased by 100.

Layout design 400A is usable to manufacture integrated circuit 500B(FIGS. 5A-5H).

Layout design 400A corresponds to a layout design of memory cells202[2,4], 202[2,5], 202[3,4] and 202[3,5] of FIGS. 2A-2B. For example,in some embodiments, the first portion 402 a corresponds to the layoutdesign of memory cell 202[2,4] of FIGS. 2A-2B, the second portion 402 bcorresponds to the layout design of memory cell 202[3,4] of FIGS. 2A-2B,the third portion 402 c corresponds to the layout design of memory cell202[2,5] of FIGS. 2A-2B, and the fourth portion 402 d corresponds to thelayout design of memory cell 202[3,5] of FIGS. 2A-2B. First portion 402a, second portion 402 b, third portion 402 c and fourth portion 402 dhave corresponding corner notches 490 a, 490 b, 490 c and 490 d (seeFIG. 4B). Corner notches 490 a, 490 b, 490 c and 490 d are similar tocorresponding corner notches 390 a, 390 b, 390 c and 390 d, and similardetailed description is therefore omitted. In some embodiments, layoutdesign 400A corresponds to a layout design of memory cells 206 a, 206 b,206 c or 206 d of the second set of memory cells 206 of FIGS. 2A-2B.

In some embodiments, the first portion 402 a of layout design 400A isusable to fabricate memory cell 202[2,4], 202[2,N], 202[M,4] or 202[M,N]of the first set of memory cells 204 of memory cell array 200A or 200B.

In some embodiments, the second portion 402 b of layout design 400A isusable to fabricate memory cell 202[1,4], 202[1,N], 202[3,4] or 202[3,N]of the first set of memory cells 204 of memory cell array 200A or 200B.

In some embodiments, the third portion 402 c of layout design 400A isusable to fabricate memory cell 202[2,1], 202[2,5], 202[M,1] or 202[M,5]of the first set of memory cells 204 of memory cell array 200A or 200B.

In some embodiments, the fourth portion 402 d of layout design 400A isusable to fabricate memory cell 202[1,1], 202[1,5], 202[3,1] or 202[3,5]of the first set of memory cells 204 of memory cell array 200A or 200B.

Active region layout patterns 404 a, 406 a, 408 a and 410 a(collectively referred to as “set of active region layout patterns 412a”) are useable to manufacture corresponding active regions 504 a 2, 506a 2, 508 a 2, 510 e of integrated circuit 500B (FIGS. 5A-5H). In someembodiments, set of active region layout patterns 412 a is referred toas OD layout patterns which define source or drain diffusion layoutpatterns of layout design 400A-400B. For example, in some embodiments,active region layout pattern 404 a is useable to manufacture the drainand source regions of NMOS transistor N1 a′ of FIGS. 4A-4B, activeregion layout pattern 406 a is useable to manufacture the drain andsource regions of PMOS transistor P1 a′ of FIGS. 4A-4B, active regionlayout pattern 408 a is useable to manufacture the drain and sourceregions of PMOS transistor P2 a′ of FIGS. 4A-4B, and active regionlayout pattern 410 a is useable to manufacture the drain and sourceregions of NMOS transistor N2 a′ and the drain and source regions ofPMOS transistor PG1 a′ of FIGS. 4A-4B.

In some embodiments, active region layout patterns 404 b, 406 b, 408 band 410 b (collectively referred to as “set of active region layoutpatterns 412 b”) are useable to manufacture active regions similar tocorresponding active regions 504 a 2, 506 a 2, 508 a 2, and 510 e ofintegrated circuit 500B (FIGS. 5A-5H). In some embodiments, activeregion layout patterns 404 c, 406 c, 408 c and 410 c (collectivelyreferred to as “set of active region layout patterns 412 c”) are useableto manufacture active regions similar to corresponding active regions504 a 2, 506 a 2, 508 a 2, and 510 e of integrated circuit 500B (FIGS.5A-5H). In some embodiments, active region layout patterns 404 d, 406 d,408 d and 410 d (collectively referred to as “set of active regionlayout patterns 412 d”) are useable to manufacture active regionssimilar to corresponding active regions 504 a 2, 506 a 2, 508 a 2, and510 e of integrated circuit 500B (FIGS. 5A-5H).

In some embodiments, active region layout patterns 404 b, 404 c and 404d are useable to manufacture the drain and source regions ofcorresponding NMOS transistors N1 b′, N1 c′ and N1 d′, active regionlayout patterns 406 b, 406 c and 406 d are useable to manufacture thedrain and source regions of corresponding PMOS transistors P1 b′, P1 c′and P1 d′, active region layout patterns 408 b, 408 c and 408 d areuseable to manufacture the drain and source regions of correspondingPMOS transistors P2 b′, P2 c′ and P2 d′, active region layout pattern410 b is useable to manufacture the drain and source regions of NMOStransistors N2 b′ and the drain and source regions of PMOS transistorPG1 b′, active region layout pattern 410 c is useable to manufacture thedrain and source regions of NMOS transistors N2 c′ and the drain andsource regions of PMOS transistor PG1 c′, and active region layoutpattern 410 d is useable to manufacture the drain and source regions ofNMOS transistors N2 d′ and the drain and source regions of PMOStransistor PG1 d′.

In some embodiments, gate layout patterns 420 a, 422 a and 424 a(collectively referred to as “set of gate layout patterns 426 a”) areusable to manufacture corresponding gate structures 520 a, 522 a and 524a of integrated circuit 500B (FIGS. 5A-5H). In some embodiments, gatelayout pattern 420 a is useable to manufacture gate regions of NMOStransistor N1 a′ and PMOS transistor P1 a′, gate layout pattern 422 a isuseable to manufacture gate regions of NMOS transistor N2 a′ and PMOStransistor P2 a′, and gate layout pattern 424 a is useable tomanufacture a gate region of PMOS transistor PG1 a′.

In some embodiments, gate layout patterns 420 b, 422 b and 424 b(collectively referred to as “set of gate layout patterns 426 b”) areusable to manufacture gate structures similar to corresponding gatestructures 520 a, 522 a and 524 a of integrated circuit 500B (FIGS.5A-5H). In some embodiments, gate layout patterns 420 c, 422 c and 424 c(collectively referred to as “set of gate layout patterns 426 c”) areusable to manufacture gate structures similar to corresponding gatestructures 520 a, 522 a and 524 a of integrated circuit 500B (FIGS.5A-5H). In some embodiments, gate layout patterns 420 d, 422 d and 424 d(collectively referred to as “set of gate layout patterns 426 d”) areusable to manufacture gate structures similar to corresponding gatestructures 520 a, 522 a and 524 a of integrated circuit 500B (FIGS.5A-5H).

In some embodiments, gate layout pattern 420 b is useable to manufacturegate regions of PMOS transistor P1 b′ and NMOS transistor N1 b′, gatelayout pattern 422 b is useable to manufacture gate regions of NMOStransistor N2 b′ and PMOS transistor P2 b′, gate layout pattern 420 c isuseable to manufacture gate regions of PMOS transistor P1 c′ and NMOStransistor N1 c′, gate layout pattern 422 c is useable to manufacturegate regions of NMOS transistor N2 c′ and PMOS transistor P2 c′, gatelayout pattern 420 d is useable to manufacture gate regions of PMOStransistor P1 d′ and NMOS transistor N1 d′, gate layout pattern 422 d isuseable to manufacture gate regions of NMOS transistor N2 d′ and PMOStransistor P2 d′, and gate layout patterns 424 b, 424 c and 424 d areuseable to manufacture corresponding gate regions of PMOS transistorsPG1 b′, PG1 c′ and PG1 d′.

In some embodiments, conductive feature layout patterns 430 a, 432 a,434 a and 436 a (collectively referred to as “set of conductive featurelayout patterns 438 a”) are usable to manufacture correspondingconductive structures 530 a, 532 a, 534 b and 536 b of integratedcircuit 500B (FIGS. 5A-5H). In some embodiments, conductive featurelayout patterns 430 b, 432 b, 434 b and 436 b (collectively referred toas “set of conductive feature layout patterns 438 b”) are usable tomanufacture conductive structures similar to corresponding conductivestructures 530 a, 532 a, 534 b and 536 b of integrated circuit 500B(FIGS. 5A-5H). In some embodiments, conductive feature layout patterns430 c, 432 c, 434 c and 436 c (collectively referred to as “set ofconductive feature layout patterns 438 c”) are usable to manufactureconductive structures similar to corresponding conductive structures 530a, 532 a, 534 b and 536 b of integrated circuit 500B (FIGS. 5A-5H). Insome embodiments, conductive feature layout patterns 430 d, 432 d, 434 dand 436 d (collectively referred to as “set of conductive feature layoutpatterns 438 d”) are usable to manufacture conductive structures similarto corresponding conductive structures 530 a, 532 a, 534 b and 536 b ofintegrated circuit 500B (FIGS. 5A-5H).

In some embodiments, via layout patterns 460 a, 462 a, 464 a, 466 a, 468a, 470 a (collectively referred to as “set of via layout patterns 458a”) are usable to manufacture corresponding vias 560 a, 562 a, 564 a,566 b, 568 b, 570 b of integrated circuit 500B (FIGS. 5A-5H). In someembodiments, via layout patterns 460 b, 462 b, 464 b, 466 b, 468 b, 470b (collectively referred to as “set of via layout patterns 458 b”) areusable to manufacture vias similar to corresponding vias 560 a, 562 a,564 a, 566 b, 568 b, 570 b of integrated circuit 500B (FIGS. 5A-5H). Insome embodiments, via layout patterns 460 c, 462 c, 464 c, 466 c, 468 c,470 c (collectively referred to as “set of via layout patterns 458 c”)are usable to manufacture vias similar to corresponding vias 560 a, 562a, 564 a, 566 b, 568 b, 570 b of integrated circuit 500B (FIGS. 5A-5H).In some embodiments, via layout patterns 460 d, 462 d, 464 d, 466 d, 468d, 470 d (collectively referred to as “set of via layout patterns 458d”) are usable to manufacture vias similar to corresponding vias 560 a,562 a, 564 a, 566 b, 568 b, 570 b of integrated circuit 500B (FIGS.5A-5H).

In some embodiments, conductive feature layout patterns 440 a and 440 b(collectively referred to as “set of conductive feature layout patterns440”) are usable to manufacture conductive structure 540 a or similarconductive structures of integrated circuit 500B (FIGS. 5A-5H).

In some embodiments, conductive feature layout patterns 442 a and 442 b(collectively referred to as “set of conductive feature layout patterns442”) are usable to manufacture corresponding conductive structures 542a and 542 b of integrated circuit 500B (FIGS. 5A-5H).

In some embodiments, conductive feature layout patterns 444 a and 444 b(collectively referred to as “set of conductive feature layout patterns444”) are usable to manufacture conductive structures similar tocorresponding conductive structures 542 a and 542 b of integratedcircuit 500B (FIGS. 5A-5H).

In some embodiments, conductive feature layout pattern 450 a(collectively referred to as “set of conductive feature layout patterns450”) is usable to manufacture conductive structure 550 b of integratedcircuit 500B (FIGS. 5A-5H).

In some embodiments, via layout patterns 474 a, 474 b (collectivelyreferred to as “set of via layout patterns 474”) are usable tomanufacture corresponding vias 574 a, 574 b of integrated circuit 500B(FIGS. 5A-5H).

In some embodiments, via layout patterns 476 a, 476 b (collectivelyreferred to as “set of via layout patterns 476”) are usable tomanufacture vias similar to corresponding vias 574 a, 574 b ofintegrated circuit 500B (FIGS. 5A-5H).

In some embodiments, via layout patterns 478 a, 478 b (collectivelyreferred to as “set of via layout patterns 478”) are usable tomanufacture via 578 b or vias similar to 578 b of integrated circuit500B (FIGS. 5A-5H).

In some embodiments, via layout patterns 480 a, 480 b (collectivelyreferred to as “set of via layout patterns 480”) are usable tomanufacture via 580 a or vias similar to via 580 a of integrated circuit500B (FIGS. 5A-5H).

In some embodiments, layout design 400A-400B has a non-rectangular shapewhich results in a smaller standard cell than other designs. In someembodiments, by having a smaller standard cell, layout design 400A-400Bcan be utilized to manufacture integrated circuits that are smaller thanother integrated circuits.

FIG. 4B is a diagram of a layout design 400B, in accordance with someembodiments.

Layout design 400B is usable to manufacture integrated circuit 500B(FIGS. 5A-5H). Layout design 400B is a variation of layout design 400Aof FIG. 4A. In comparison with layout design 400A of FIG. 4A, layoutdesign 400B further includes a first well layout pattern 416 and asecond well layout pattern 414.

First well layout pattern 416 extends in the second direction Y, and islocated on the fifth layout level. First well layout pattern 416 isuseable to manufacture a first well 502 (e.g., at least portions 502 a,502 b) of integrated circuit 500B (FIGS. 5A-5H).

First well layout pattern 416 includes layout patterns 456 a, 456 b, 456c and 456 d.

Layout pattern 456 a extends in the second direction Y and is belowactive region layout patterns 404 a and 404 b. Layout pattern 456 a isadjacent to a side 452 a of the first portion 402 a or the secondportion 402 b of layout design 400B. Layout pattern 456 a is useable tomanufacture portion 502 a of first well 502 of integrated circuit 500B(FIGS. 5A-5H). Layout pattern 456 a has width W1 (not labelled) in thefirst direction X.

Layout pattern 456 b extends in the second direction Y and is belowactive region layout patterns 404 c and 404 d. Layout pattern 456 b isadjacent to a side 452 c of the third portion 402 c or the fourthportion 402 d of layout design 400B. Layout pattern 456 b is useable tomanufacture a portion of first well 502 similar to portion 502 a ofintegrated circuit 500B (FIGS. 5A-5H). Layout pattern 456 b has width W1(not labelled) in the first direction X.

Layout pattern 456 c extends in the first direction X and is below aportion of active region layout patterns 410 a and 410 c. In someembodiments, a side of layout pattern 456 c is aligned with a first sideof layout pattern 454 b along line 452 d 1 in the first direction X.Layout pattern 456 c is useable to manufacture portion 502 b of firstwell 502 of integrated circuit 500B (FIGS. 5A-5H). Layout pattern 456 chas width W2 (not labelled) in the first direction X.

Layout pattern 456 d extends in the first direction X and is below aportion of active region layout patterns 410 b and 410 d. In someembodiments, a side of layout pattern 456 d is aligned with a secondside of layout pattern 454 b along line 452 d 2 in the first directionX. Layout pattern 456 d is useable to manufacture a portion of firstwell 502 similar to portion 502 b of integrated circuit 500B (FIGS.5A-5H). Layout pattern 456 d has width W2 (not labelled) in the firstdirection X.

Second well layout pattern 414 extends in the second direction Y, and islocated on the fifth layout level. Second well layout pattern 414 isuseable to manufacture a second well 502′ (e.g., at least portions 502c, 502 d) of integrated circuit 500B (FIGS. 5A-5H). Second well layoutpattern 414 includes layout patterns 454 a, 454 b and 454 c.

Layout pattern 454 a extends in the second direction Y and is belowactive region layout patterns 406 a, 406 b, 408 a and 408 b. Layoutpattern 454 a is useable to manufacture portion 502 c of second well502′ of integrated circuit 500B (FIGS. 5A-5H). Layout pattern 454 a haswidth W3 (not labelled) in the first direction X.

Layout pattern 454 b extends in the first direction X and is below aportion of active region layout patterns 410 a, 410 b, 410 c and 410 d.Layout pattern 454 b is positioned over center lines 452 b 1, 452 b 2 oflayout design 400B. In some embodiments, a center of layout pattern 454b is aligned with center lines 452 b 1 and 452 b 2 of layout design400B. In some embodiments, the first side of layout pattern 454 b isaligned with line 452 d 1 in the first direction X. In some embodiments,the second side of layout pattern 454 b is aligned with line 452 d 2 inthe first direction X. Layout pattern 454 b is useable to manufacture atleast portion 502 d of the second well 502′ of integrated circuit 500B(FIGS. 5A-5H). In some embodiments, layout pattern 454 b is useable tomanufacture portions similar to portion 502 d of the second well 502′ ofintegrated circuit 500B (FIGS. 5A-5H). Layout pattern 454 b has width W2(not labelled) in the first direction X.

Layout pattern 454 c extends in the second direction Y and is belowactive region layout patterns 406 c, 406 d, 408 c and 408 d. Layoutpattern 454 c is useable to manufacture a portion of second well 502′similar to portion 502 c of integrated circuit 500B (FIGS. 5A-5H).Layout pattern 454 c has width W3 (not labelled) in the first directionX.

In some embodiments, layout patterns 454 a, 454 b and 454 c are part ofa same continuous layout pattern (e.g., second well layout pattern 414).

Layout pattern 454 a is between layout patterns 456 a and each of layoutpatterns 454 b, 456 c and 456 d. Layout pattern 454 c is between layoutpatterns 456 b and each of layout patterns 454 b, 456 c and 456 d.Layout pattern 454 b is between layout patterns 456 c and 456 d. Layoutpattern 454 b is between layout patterns 454 a and 454 c.

In some embodiments, width W1, W2 or W3 is the same as another width ofwidth W1, W2 or W3. In some embodiments, width W1, W2 or W3 is differentfrom another width of width W1, W2 or W3.

Other configurations or quantities of first well layout pattern 416 orsecond well layout pattern 414 are within the scope of the presentdisclosure. Other configurations or quantities of layout patterns 454 a,454 b, 454 c, 456 a, 456 b, 456 c or 456 d are within the scope of thepresent disclosure.

FIGS. 5A, 5B, 5C, 5D, 5E, 5F, 5G and 5H are diagrams of an integratedcircuit 500A or 500B, in accordance with some embodiments.

FIG. 5A is a cross-sectional view of an integrated circuit 500A or 500Bcorresponding to layout design 300B or 400B as intersected by planeA-A′, respectively.

FIG. 5B is a cross-sectional view of an integrated circuit 500A or 500Bcorresponding to layout design 300B or 400B as intersected by planeB-B′, respectively.

FIG. 5C is a cross-sectional view of an integrated circuit 500A or 500Bcorresponding to layout design 300B or 400B as intersected by planeC-C′, respectively.

FIG. 5D is a cross-sectional view of an integrated circuit 500Acorresponding to layout design 300B as intersected by plane D-D′, andFIG. 5E is a cross-sectional view of an integrated circuit 500Bcorresponding to layout design 400B as intersected by plane E-E′.

FIG. 5F is a cross-sectional view of an integrated circuit 500A or 500Bcorresponding to layout design 300B or 400B as intersected by planeF-F′, respectively.

FIG. 5G is a cross-sectional view of an integrated circuit 500Acorresponding to layout design 300B as intersected by plane G-G′, andFIG. 5H is a cross-sectional view of an integrated circuit 500Acorresponding to layout design 400B as intersected by plane H-H′.

Integrated circuit 500A is manufactured by the first portion 302 a oflayout design 300B, and integrated circuit 500B is manufactured by thefirst portion 402 a of layout design 400B. In some embodiments, secondportion 302 b, third portion 302 c and fourth portion 302 d of layoutdesign 300B are usable to manufacture an integrated circuit similar tointegrated circuit 500A. In some embodiments, second portion 402 b,third portion 402 c and fourth portion 402 d of layout design 400B areusable to manufacture an integrated circuit similar to integratedcircuit 500B.

Structural relationships including alignment, lengths and widths, aswell as configurations of integrated circuit 500A-500B are similar tothe structural relationships and configurations of layout design300A-300B of FIGS. 3A-3B and layout design 400A-400B of FIGS. 4A-4B, andwill not be described in FIGS. 5A-5H for brevity.

For brevity, integrated circuits 500A and 500B are described below asthey pertain to FIGS. 5A-5H. For brevity, elements with the samereference numeral in integrated circuits 500A and 500B are describedwith reference to either integrated circuit 500A or 500B, and similardetailed description is omitted.

Integrated circuit 500B is a variation of integrated circuit 500A. Incomparison with integrated circuit 500A, integrated circuit 500B doesnot include first well 501 and second well 501′. In comparison withintegrated circuit 500A, first well 502 of integrated circuit 500Breplaces first well 501, and second well 502′ of integrated circuit 500Breplaces second well 501.

Integrated circuit 500A includes a first well 501 and a second well501′. Each of the first well 501 and the second well 501′ is located onat least the first level of integrated circuit 500A, and extends in thesecond direction Y.

The first well 501 of integrated circuit 500A includes dopants of afirst type. The second well 501′ of integrated circuit 500A includesdopants of a second type different from the first type. In someembodiments, the first type is an N-type dopant, the second type is aP-type dopant, and the first well 501 of integrated circuit 500A is anN-well, and the second well 501′ of integrated circuit 500A is a P-well.In some embodiments, the first type is a P-type dopant, the second typeis an N-type dopant, and the first well 501 of integrated circuit 500Ais a P-well, and the second well 501′ of integrated circuit 500A is anN-well.

The first well 501 of integrated circuit 500A includes a first portion501 a and a second portion 501 b.

The first portion 501 a of the first well 501 extends in the seconddirection Y and is adjacent to a first side 590 a of integrated circuit500A. In some embodiments, the first side 590 a of integrated circuit500A corresponds to line 352 a of layout design 300B. The first portion501 a of the first well 501 is located on at least the first level ofintegrated circuit 500A.

The second portion 501 b of the first well 501 extends in the seconddirection Y and is adjacent to a second side 590 b of integrated circuit500A. In some embodiments, the second side 590 b of integrated circuit500A corresponds to line 352 b 1 of layout design 300B. The secondportion of the first well 501 is located on at least the first level ofintegrated circuit 500A.

The second well 501′ of integrated circuit 500A includes a portion 501c. The second well 501′ is between the first portion 501 a of the firstwell 501 and the second portion 501 b of the first well 501.

Portion 501 c of the second well 501′ extends in the second direction Yand is between the first portion 501 a of the first well 501 and thesecond portion 501 b of the first well 501. Portion 501 c of the secondwell 501′ is located on at least the first level of integrated circuit500A. Other quantities or configurations of the first well 501 or thesecond well 501′ are within the scope of the present disclosure.

Integrated circuit 500A or 500B includes a set of active regions 504extending in the second direction Y. The set of active regions 504 islocated on a first level of integrated circuit 500A or 500B.

The set of active regions 504 includes one or more of active regions 504a 1, 506 a 1, 508 a 1 or 510 a 1. Each of the active regions 504 a 1,506 a 1, 508 a 1, 510 a 1 of the set of active regions 504 is separatedfrom an adjacent active region of the set of active regions 504 in thefirst direction X by a first pitch (not labelled).

Active region 504 a 1 is adjacent to the first side 590 a of integratedcircuit 500A. Active region 510 a 1 is adjacent to the second side 590 bof integrated circuit 500A. The second side 590 b of integrated circuit500A is opposite from the first side 590 a of integrated circuit 500A.

Active region 504 a 1 of the set of active regions 504 is embedded inthe first portion 501 a of the first well 501 of integrated circuit500A.

Active region 510 a 1 of the set of active regions 504 is embedded inthe second portion 501 b of the first well 501 of integrated circuit500A.

Active region 506 a 1 or 508 a 1 of the set of active regions 504 isembedded in portion 501 c of the second well 501′ of integrated circuit500A.

Active regions 506 a 1 and 508 a 1 includes dopants of the first type.Active regions 504 a 1 and 510 a 1 includes dopants of the second type.In some embodiments, the first type is an N-type dopant, the second typeis a P-type dopant, and therefore active regions 504 a 1 and 510 a 1 areeach P-type active regions embedded in first well 501 (which is anN-well), and active regions 506 a 1 and 508 a 1 are each N-type activeregions embedded in second well 501′ (which is a P-well). In someembodiments, the first type is a P-type dopant, the second type is anN-type dopant, and therefore active regions 504 a 1 and 510 a 1 are eachN-type active regions embedded in first well 501 (which is a P-well),and active regions 506 a 1 and 508 a 1 are each P-type active regionsembedded in second well 501′ (which is an N-well).

In some embodiments, a length of at least one of active region 504 a 1,506 a 1, 508 a 1 or 510 a 1 in the second direction Y is different froma length of another of active region 504 a 1, 506 a 1, 508 a 1 or 510 a1 in the second direction Y. In some embodiments, a length of at leastone of active region 504 a 1, 506 a 1, 508 a 1 or 510 a 1 in the seconddirection Y is the same as a length of another of active region 504 a 1,506 a 1, 508 a 1 or 510 a 1 in the second direction Y. Other quantitiesor configurations of the set of active regions 504 are within the scopeof the present disclosure.

Integrated circuit 500A or 500B includes a set of gates 527 extending inthe first direction X. The set of gates 527 overlaps the set of activeregions 504 of integrated circuit 500A or the set of active regions 505of integrated circuit 500B. The set of gates 527 is located on a secondlevel of integrated circuit 500A or 500B. The second level is differentfrom the first level of integrated circuit 500A or 500B. In someembodiments, the second level of integrated circuit 500A or 500B isreferred to as the POLY level.

The set of gates 527 includes one or more of gate structures 520 a, 522a or 524 a. Each of gate structures 520 a and 524 a are separated fromgate structure 522 a in the second direction Y by a gate pitch (notlabelled). Gate structures 520 a and 524 a are separated from each otherin the first direction X. Other quantities or configurations of the setof gates 527 are within the scope of the present disclosure.

Integrated circuit 500A or 500B includes conductive structures 504 b,504 c, 504 d, 504 e, 504 f, 510 b, 510 c, 510 d, 510 e, 510 f, 516 e,516 f and 520 f (collectively referred to as a “set of contacts 521”).

Set of contacts 521 extends in the first direction X or the seconddirection Y. The set of contacts 521 is over the set of active regions504 of integrated circuit 500A or the set of active regions 505 ofintegrated circuit 500B. The set of contacts 521 is located on thesecond level of integrated circuit 500A or 500B. In some embodiments,the second level of integrated circuit 500A or 500B is referred to asthe metal diffusion (MD) level.

The set of contacts 521 electrically couples the set of active regions504 of integrated circuit 500A or the set of active regions 505 ofintegrated circuit 500B to upper levels (e.g., M0, M1 or M2) ofcorresponding integrated circuit 500A or 500B. Conductive structures 504b, 510 b electrically couple corresponding vias 506 b, 512 b to activeregion 504 a 1 or 504 a 2 (part of integrated circuit 500B). Conductivestructures 504 c, 510 c electrically couple corresponding vias 506 c,512 c to active region 506 a 1 or 506 a 2 (part of integrated circuit500B). Conductive structures 504 d, 510 d electrically couplecorresponding vias 506 d, 512 d to active region 508 a 1 or 508 a 2(part of integrated circuit 500B). Conductive structures 504 e, 510 e,516 e electrically couple corresponding vias 506 e, 512 e, 518 e toactive region 510 a 1. Conductive structures 504 f, 510 f electricallycouple corresponding vias 506 f, 512 f to active region 510 b.Conductive structures 516 f, 520 f electrically couple correspondingvias 518 f, 522 f to active region 510 c. Other quantities orconfigurations of the set of contacts 521 are within the scope of thepresent disclosure.

Integrated circuit 500A or 500B includes conductive structures 508 b,508 c, 508 d, 508 e, 508 f, 514 b, 514 e, 514 f, 516 c, 516 d, 520 e,524 f (collectively referred to as a “set of conductive structures529”). Set of conductive structures 529 extends in the first direction Xor the second direction Y. The set of conductive structures 529 is overthe set of active regions 504 of integrated circuit 500A or the set ofactive regions 505 of integrated circuit 500B. The set of conductivestructures 529 is over at least the set of contacts 521 or the set ofgates 527. The set of conductive structures 529 is located on a thirdlevel of integrated circuit 500A or 500B. The third level of integratedcircuit 500A or 500B is different from the first level of integratedcircuit 500A or 500B and the second level of integrated circuit 500A or500B. In some embodiments, the third level of integrated circuit 500A or500B is referred to as the metal zero (M0) level.

The set of conductive structures 529 electrically couples the set ofactive regions 504 of integrated circuit 500A or the set of activeregions 505 of integrated circuit 500B to upper levels (e.g., M1 or M2)of corresponding integrated circuit 500A or 500B. In some embodiments,the set of conductive structures 529 electrically couples the set ofgates 527 to upper levels (e.g., M1 or M2) of integrated circuit 500A or500B. Other quantities or configurations of the set of conductivestructures 529 are within the scope of the present disclosure.

Integrated circuit 500A or 500B includes vias 504 g, 506 b, 506 c, 506d, 506 e, 506 f, 512 b, 512 c, 512 d, 512 e, 512 f, 514 c, 514 d, 518 e,518 f and 522 f (collectively referred to as a “set of vias 523”)between the set of conductive structures 529 and the set of activeregions 504 of integrated circuit 500A or the set of active regions 505of integrated circuit 500B. The set of vias 523 electrically couple theset of conductive structures 529 to the set of active regions 504 ofintegrated circuit 500A or the set of active regions 505 of integratedcircuit 500B. In some embodiments, one or more vias of the set of vias523 is located where one or more conductive structures of the set ofconductive structures 529 is over one or more active regions of the setof active regions 504 of integrated circuit 500A or one or more activeregions of the set of active regions 505 of integrated circuit 500B.

Vias 506 b, 512 b electrically couple corresponding conductivestructures 508 b, 514 b to corresponding conductive structures 504 b,510 b. Vias 506 c, 512 c electrically couple corresponding conductivestructures 508 c, 516 c to corresponding conductive structures 504 c,510 c. Vias 506 d, 512 d electrically couple corresponding conductivestructures 508 d, 516 d to corresponding conductive structures 504 d,510 d. Vias 506 e, 512 e, 518 e electrically couple correspondingconductive structures 508 e, 514 e, 520 e to corresponding conductivestructures 504 e, 510 e, 516 e. Vias 506 f, 522 f electrically couplecorresponding conductive structures 508 f, 524 f to correspondingconductive structures 504 f, 520 f. Vias 512 f, 518 f electricallycouple conductive structure 514 f to corresponding conductive structures510 f, 516 f.

Each of vias 514 c, 514 d, 504 g is above corresponding gate structures522 a, 520 a, 524 a. Vias 514 c, 514 d, 504 g electrically couplecorresponding conductive structures 516 c, 516 d, 506 g to correspondinggate structures 522 a, 520 a, 524 a. Vias 514 c, 514 d, 504 g are abovecorresponding gate structures 522 a, 520 a, 524 a. In some embodiments,the set of vias 523 is between the first set of conductive structures538 and the set of gates 527. Via 504 g of the set of vias 523 islocated where conductive structure 540 a of the first set of conductivestructures 538 is over gate structure 524 a of the set of gates 527.

Set of vias 523 is in the via over diffusion (VD) level or the via overgate (VG) level of integrated circuit 500A or 500B. The VG or VD levelof integrated circuit 500A or 500B is between the second level and thethird level. In some embodiments, vias 514 c, 514 d, 504 g are in the VGlevel of integrated circuit 500A or 500B. In some embodiments, vias 506b, 506 c, 506 d, 506 e, 506 f, 512 b, 512 c, 512 d, 512 e, 512 f, 518 e,518 f and 522 f are in the VD level of integrated circuit 500A or 500B.Other quantities or configurations of the set of vias 523 are within thescope of the present disclosure.

Integrated circuit 500A or 500B includes conductive structures 524 e,528 f, 530 a, 532 a, 534 a, 534 b, 536 a, 536 b, 540 a, 542 a and 542 b(collectively referred to as a “first set of conductive structures538”). The first set of conductive structures 538 extends in the firstdirection X. Each conductive structure of the first set of conductivestructures 538 is separated from an adjacent conductive structure of thefirst set of conductive structures 538 feature in at least the firstdirection X or the second direction Y. The first set of conductivestructures 538 is over at least the set of active regions 504 ofintegrated circuit 500A, the set of active regions 505 of integratedcircuit 500B, the set of gates 527, or the set of contacts 521. Thefirst set of conductive structures 538 is located on a fourth level ofintegrated circuit 500A or 500B. The fourth level of integrated circuit500A or 500B is different from the first level of integrated circuit500A or 500B, the second level of integrated circuit 500A or 500B andthe third level of integrated circuit 500A or 500B. In some embodiments,the fourth level of integrated circuit 500A or 500B is referred to asthe metal one (M1) level.

In some embodiments, conductive structure 540 a corresponds to the wordline WL1 of memory cell 100 of FIG. 1 or word lines WL[1], . . . ,WL[2M] of memory cell array 200A-200B of FIGS. 2A-2B.

The first set of conductive structures 538 is electrically coupled tothe set of active regions 504 of integrated circuit 500A or the set ofactive regions 505 of integrated circuit 500B. In some embodiments, thefirst set of conductive structures 538 is electrically coupled to theset of gates 527. Other quantities or configurations of the first set ofconductive structures 538 are within the scope of the presentdisclosure.

Integrated circuit 500A or 500B includes vias 522 e, 526 f, 560 a, 562a, 564 a, 566 a, 566 b, 568 a, 568 b, 570 a, 570 b, 574 a, 574 b and 580a (collectively referred to as a “first set of vias 572”) between thefirst set of conductive structures 538 and the set of active regions 504of integrated circuit 500A or the set of active regions 505 ofintegrated circuit 500B. The first set of vias 572 electrically couplethe first set of conductive structures 538 to the set of active regions504 of integrated circuit 500A or the set of active regions 505 ofintegrated circuit 500B. In some embodiments, one or more vias of thefirst set of vias 572 is located where one or more conductive structuresof the first set of conductive structures 538 overlaps one or moreactive regions of the set of active regions 504 of integrated circuit500A or one or more active regions of the set of active regions 505 ofintegrated circuit 500B.

Vias 560 a, 574 a electrically couple corresponding conductivestructures 530 a, 542 a to corresponding conductive structures 508 b,514 b. Vias 562 a, 574 b electrically couple corresponding conductivestructures 530 a, 542 b to corresponding conductive structures 516 c,508 c. Via 564 a electrically couples conductive structure 532 a toconductive structure 508 d. Vias 566 a, 566 b electrically couplecorresponding conductive structures 534 a, 534 b to conductivestructures 516 d. Vias 568 a, 570 a, 522 e electrically couplecorresponding conductive structures 536 a, 534 a, 524 e to correspondingconductive structures 508 e, 514 e, 520 e. Vias 568 b, 570 b, 526 felectrically couple corresponding conductive structures 536 b, 534 b,528 f to corresponding conductive structures 508 f, 514 f, 524 f. Via580 a electrically couples conductive structure 540 a to conductivestructure 506 g.

First set of vias 572 is in the via zero (V0) level of integratedcircuit 500A or 500B. The V0 level of integrated circuit 500A or 500B isbetween the third level and the fourth level. In some embodiments, theV0 level of integrated circuit 500A or 500B is between the M1 level andthe M0 level. Other quantities or configurations of the first set ofvias 572 are within the scope of the present disclosure.

Integrated circuit 500A or 500B includes conductive structures 550 a and550 b (collectively referred to as a “second set of conductivestructures 552”). The second set of conductive structures 552 extends inthe first direction X. Each conductive structure of the second set ofconductive structures 552 is separated from an adjacent conductivestructure of the second set of conductive structures 552 in at least thefirst direction X or the second direction Y. In some embodiments, thesecond set of conductive structures 552 is over one or more of the setof active regions 504 of integrated circuit 500A, the set of activeregions 505 of integrated circuit 500B or the set of contacts 521.

The second set of conductive structures 552 is located on a fifth levelof integrated circuit 500A or 500B. The fifth level of integratedcircuit 500A or 500B is different from the first level of integratedcircuit 500A or 500B, the second level of integrated circuit 500A or500B, the third level of integrated circuit 500A or 500B and the fourthlevel of integrated circuit 500A or 500B. In some embodiments, the fifthlevel of integrated circuit 500A or 500B is referred to as the metal two(M2) level.

In some embodiments, the second set of conductive structure 552 overlapsthe set of active regions 504 of integrated circuit 500A or the set ofactive regions 505 of integrated circuit 500B. Conductive structure 550a overlaps active region 510 a of the set of active regions 504 ofintegrated circuit 500A and the second side 590 b of integrated circuit500A. Conductive structure 550 b overlaps active region 510 c of the setof active regions 505 of integrated circuit 500B and the second side 590b of integrated circuit 500B. In some embodiments, conductive structure550 a or 550 b corresponds to the bit line BL1 of memory cell 100 ofFIG. 1 or bit lines BL[1], . . . , BL[2N] of memory cell array 200A-200Bof FIGS. 2A-2B.

In some embodiments, the second set of conductive structures 552 iselectrically coupled to the set of active regions 504 of integratedcircuit 500A or the set of active regions 505 of integrated circuit500B. Conductive structure 550 a is electrically coupled to activeregion 510 a of integrated circuit 500A. Conductive structure 550 b iselectrically coupled to active region 510 c of integrated circuit 500B.Other quantities or configurations of the second set of conductivestructures 552 are within the scope of the present disclosure.

Integrated circuit 500A or 500B includes vias 578 a and 578 b(collectively referred to as a “set of vias 576”) between the second setof conductive structures 552 and the first set of conductive structures538. The set of vias 576 electrically couple the second set ofconductive structures 552 to the first set of conductive structures 538.Vias 578 a, 578 b electrically couple corresponding conductivestructures 550 a, 550 b to corresponding conductive structures 524 e,528 f. In some embodiments, the set of vias 576 electrically couple thesecond set of conductive structures 552 to the set of active regions 504of integrated circuit 500A or the set of active regions 505 ofintegrated circuit 500B.

In some embodiments, one or more vias of the set of vias 576 is locatedwhere one or more conductive structures of the second set of conductivestructures 538 overlaps one or more active regions of the set of activeregions 504 of integrated circuit 500A or one or more active regions ofthe set of active regions 505 of integrated circuit 500B.

First set of vias 572 is in the via one (V1) level of integrated circuit500A or 500B. The V1 level of integrated circuit 500A or 500B is betweenthe fourth level and the fifth level. In some embodiments, the V1 levelof integrated circuit 500A or 500B is between the M2 level and the M1level. Other quantities or configurations of the set of vias 572 arewithin the scope of the present disclosure.

Integrated circuit 500B is a variation of integrated circuit 500A. Incomparison with integrated circuit 500A, a first well 502 of integratedcircuit 500B replaces first well 501, a second well 502′ of integratedcircuit 500B replaces second well 501, and a set of active regions 505of integrated circuit 500B replaces the set of active regions 504.

Integrated circuit 500B includes first well 502 and second well 502′.Each of the first well 502 and the second well 502′ is located on atleast the first level of integrated circuit 500B, and extends in atleast the second direction Y.

The first well 502 of integrated circuit 500B includes dopants of thesecond type. The second well 502′ of integrated circuit 500B includesdopants of the first type. In some embodiments, the first type is anN-type dopant, the second type is a P-type dopant, and the first well502 of integrated circuit 500B is a P-well, and the second well 502′ ofintegrated circuit 500B is an N-well. In some embodiments, the firsttype is a P-type dopant, the second type is an N-type dopant, and thefirst well 502 of integrated circuit 500B is an N-well, and the secondwell 502′ of integrated circuit 500B is a P-well.

The first well 502 of integrated circuit 500B includes a first portion502 a and a second portion 502 b.

The first portion 502 a of the first well 502 extends in the seconddirection Y and is adjacent to the first side 590 a of integratedcircuit 500B. In some embodiments, the first side 590 a of integratedcircuit 500B corresponds to line 352 a of layout design 400B. The firstportion 502 a of the first well 502 is located on at least the firstlevel of integrated circuit 500B.

The second portion 502 b of the first well 502 extends in the seconddirection Y and is adjacent to the second side 590 b of integratedcircuit 500B. In some embodiments, the second side 590 b of integratedcircuit 500B corresponds to line 352 b 1 of layout design 400B. Thesecond portion of the first well 502 is located on at least the firstlevel of integrated circuit 500B. Other quantities or configurations ofthe first well 502, the first portion 502 a of the first well 502 or thesecond portion 502 b of the first well 502 are within the scope of thepresent disclosure.

The second well 502′ of integrated circuit 500B includes a first portion502 c and a second portion 502 d.

The first portion 502 c of the second well 502′ extends in the seconddirection Y and is adjacent to the first portion 502 a of the first well502. The first portion 502 c of the second well 502′ is located on atleast the first level of integrated circuit 500B.

The second portion 502 d of the second well 502′ extends in at least thefirst direction X or the second direction Y. The second portion 502 d ofthe second well 502′ is adjacent to each of the second side 590 b ofintegrated circuit 500B, the second portion 502 b of the first well 502and the first portion 502 c of the second well 502′. The second portion502 d of the second well 502′ is located on at least the first level ofintegrated circuit 500B.

The first portion 502 c of the second well 502′ is between the firstportion 502 a of the first well 502 and each of the second portion 502 bof the first well 502 and the second portion 502 d of the second well502′. Other quantities or configurations of the second well 502′, thefirst portion 502 c of the second well 502′ or the second portion 502 dof the second well 502′ are within the scope of the present disclosure.

Integrated circuit 500B includes a set of active regions 505 extendingin the second direction Y. The set of active regions 505 is located onthe first level of integrated circuit 500B.

The set of active regions 505 includes one or more of active regions 504a 2, 506 a 2, 508 a 2 or 510 e. Each of the active regions 504 a 2, 506a 2, 508 a 2 or 510 e of the set of active regions 505 is separated froman adjacent active region of the set of active regions 505 in the firstdirection X by the first pitch (not labelled).

Active region 510 e includes an active region 510 b and an active region510 c. Active region 510 b and active region 510 c are separated fromeach other in the second direction Y.

Active region 504 a 2 is adjacent to the first side 590 a of integratedcircuit 500B. Active region 510 e is adjacent to the second side 590 bof integrated circuit 500B.

Active region 504 a 2 of the set of active regions 505 is embedded inthe first portion 502 a of the first well 502 of integrated circuit500B.

Active region 510 e of the set of active regions 505 is embedded in eachof the second portion 502 b of the first well 502 of integrated circuit500B and the second portion 502 d of the second well 502′ of integratedcircuit 500B. Active region 510 b is embedded in the second portion 502b of the first well 502 of integrated circuit 500B. Active region 510 cis embedded in the second portion 502 d of the second well 502′ ofintegrated circuit 500B.

Active region 506 a 2 or 508 a 2 of the set of active regions 505 isembedded in the first portion 502 c of the second well 502′ ofintegrated circuit 500B.

Active regions 504 a 2 and 510 b includes dopants of the first type.Active regions 506 a 2, 508 a 2 and 510 c includes dopants of the secondtype.

In some embodiments, the first type is an N-type dopant, the second typeis a P-type dopant, and therefore active regions 504 a 2 and 510 b areeach N-type active regions embedded in the first well 502 (which is aP-well), and active regions 506 a 2, 508 a 2 and 510 c are each P-typeactive regions embedded in the second well 502′ (which is an N-well). Insome embodiments, the first type is a P-type dopant, the second type isan N-type dopant, and therefore active regions 504 a 2 and 510 b areeach P-type active regions embedded in the first well 502 (which is anN-well), and active regions 506 a 2, 508 a 2 and 510 c are each N-typeactive regions embedded in the second well 502′ (which is a P-well).

In some embodiments, a length of at least one of active region 504 a 2,506 a 2, 508 a 2, 510 b, 510 c, or 510 e in the second direction Y isdifferent from a length of another of active region 504 a 2, 506 a 2,508 a 2, 510 b, 510 c, or 510 e in the second direction Y. In someembodiments, a length of at least one of active region 504 a 2, 506 a 2,508 a 2, 510 b, 510 c, or 510 e in the second direction Y is the same asa length of another of active region 504 a 2, 506 a 2, 508 a 2, 510 b,510 c, or 510 e in the second direction Y. Other quantities orconfigurations of the set of active regions 505 are within the scope ofthe present disclosure.

In some embodiments, integrated circuit 500A-500B occupies less areathan other integrated circuits. In some embodiments, by occupying lessarea than other integrated circuits, integrated circuit 500A-500B isutilized as part of a memory cell array 200A-200B that is densercompared with other approaches. In some embodiments, by being utilizedas part of a denser memory cell array 200A-200B, memory cell array200A-200B has a larger memory capacity than other approaches.

FIG. 6 is a diagram of a layout design 600, in accordance with someembodiments.

A portion of layout design 600 is usable to manufacture integratedcircuit 500A or 500B (FIGS. 5A-5H).

Layout design 600 comprises a first set of tiles 602 and a second set oftiles 604 arranged as an array of tiles. In some embodiments, at leastone tile of the first set of tiles 602 corresponds to layout design 300Aor 300B, and at least one tile of the second set of tiles 604corresponds to layout design 400A or 400B. In some embodiments, at leastone tile of the first set of tiles 602 corresponds to layout design 400Aor 400B, and at least one tile of the second set of tiles 604corresponds to layout design 300A or 300B. In some embodiments, a shapeof the first set of tiles 602 and a shape of the second set of tiles 604are non-rectangular, and therefore the shape of layout design 600 canalso be a non-rectangular shape.

The first set of tiles 602 extends in a third direction S. The thirddirection S relates to the first direction X and the second direction Y.For example, in some embodiments, the third direction S is rotated fromthe first direction X towards the second direction Y by an angle α. Insome embodiments, the angle α ranges from about 0 degrees to about 180degrees. The angle α is expressed by formula 2 (described below). Insome embodiments, the third direction S is equal to the first directionX or the second direction Y. In some embodiments, the third direction Sis different from the first direction X or the second direction Y. Thefirst set of tiles 602 comprises one or more of tiles 608[1,1],608[2,1], . . . , 608[P,1], 608[1,3], 608[2,3], . . . , 608[P,3],608[1,Q−1], 608[2,Q−1], . . . , 608[P−1,Q−1], where P is a positiveinteger corresponding to the number of columns in the array of tiles andQ is a positive integer corresponding to the number of rows in the arrayof tiles.

Each tile of the first set of tiles 602 extends in the first directionX. Each tile of the first set of tiles 602 has four notches (notlabelled for ease of illustration). In some embodiments, the fournotches (not labelled for ease of illustration) of each tile of thefirst set of tiles 602 corresponds to corner notches 390 a, 390 b, 390 cand 390 d of the set of corner notches 390 of FIGS. 3A-3B. For example,tile 608[P,Q−1] has notches 630 a, 630 b, 630 c and 630 d. In someembodiments, notches 630 a, 630 b, 630 c and 630 d are correspondingcorner notches 390 a, 390 b, 390 c and 390 d of FIGS. 3A-3B. Each notch630 a, 630 b, 630 c and 630 d is located in a corresponding corner oftile 608[P,Q−1]. In some embodiments, each notch (not labelled for easeof illustration) of each tile of the first set of tiles 602 is locatedin a corresponding corner of the tile of the first set of tiles 602. Acenter of each tile of the first set of tiles 602 is offset from acenter of an adjacent tile of the first set of tiles 602 in the seconddirection Y by a distance D1. For example, the center of tile 608[1,1]is separated from the center of tile 608[2,1] in the second direction Yby the distance D1.

A center of each tile of the first set of tiles 602 is separated from acenter of an adjacent tile of the first set of tiles 602 in the thirddirection S by a distance D2. For example, a center of tile 608[1,1] isseparated from a center of tile 608[2,1] in the third direction S by thedistance D2.

A center of each tile of the first set of tiles 602 is separated from acenter of an adjacent tile of the first set of tiles 602 in the firstdirection X by a distance D3. For example, the center of tile 608[1,1]is separated from the center of tile 608[2,1] in the first direction Xby the distance D3.

A relationship between distances D1, D2 and D3 is expressed by formula1.

D2=(D1² +D3²)^(0.5)  (1)

The second set of tiles 604 extends in the third direction S. Arelationship between angle α and distances D2 and D3 is expressed byformula 2.

α=ArcCos(D3/D2)  (2)

The second set of tiles 604 comprises one or more of tiles 608[1,2],608[2,2], . . . , 608[P,2], 608[1,4], 608[2,4], . . . , 608[P,4],608[1,Q], 608[2,Q], . . . , 608[P,Q]. The second set of tiles 604 isseparated from the first set of tiles 602 in the second direction Y.

The first set of tiles 602 and the second set of tiles 604 alternatewith each other in the second direction Y. Each tile of the second setof tiles 604 extends in the first direction X. Each tile of the secondset of tiles 604 has four notches (not labelled for ease ofillustration). In some embodiments, the four notches (not labelled forease of illustration) of each tile of the second set of tiles 604corresponds to corner notches 490 a, 490 b, 490 c and 490 d of the setof corner notches 490 of FIGS. 4A-4B. For example, tile 608[P,Q] hasnotches 640 a, 640 b, 640 c and 640 d. In some embodiments, notches 640a, 640 b, 640 c and 640 d are corresponding corner notches 490 a, 490 b,490 c and 490 d of FIGS. 4A-4B. Each notch 640 a, 640 b, 640 c and 640 dis located in a corresponding corner of tile 608[P,Q]. In someembodiments, each notch (not labelled for ease of illustration) of eachtile of the second set of tiles 604 is located in a corresponding cornerof the tile of the second set of tile 604. A center of each tile of thesecond set of tiles 604 is offset from a center of an adjacent tile ofthe second set of tiles 604 in the second direction Y by a distance D1′.For example, the center of tile 608[1,2] is separated from the center oftile 608[2,2] in the second direction Y by the distance D1′.

A center of each tile of the second set of tiles 604 is separated from acenter of an adjacent tile of the second set of tiles 604 in the thirddirection S by a distance D2′. For example, a center of tile 608[1,2] isseparated from a center of tile 608[2,2] in the third direction S by thedistance D2′.

A center of each tile of the second set of tiles 604 is separated from acenter of an adjacent tile of the second set of tiles 604 in the firstdirection X by a distance D3′. For example, the center of tile 608[1,2]is separated from the center of tile 608[2,2] in the first direction Xby the distance D3′.

A relationship between distances D1′, D2′ and D3′ is expressed byformula 3.

D2′=(D1′² +D3′²)^(0.5)  (3)

A relationship between angle α and distances D2′ and D3′ is expressed byformula 4.

α=ArcCos(D3′/D2′)  (4)

A center of a tile of the second set of tiles 604 is separated from acenter of an adjacent tile of the first set of tiles 604 in a fourthdirection T by a distance D4. For example, the center of tile 608[1,1]is separated from the center of tile 608[1,2] in the fourth direction Tby the distance D4. The fourth direction T relates to the firstdirection X and the second direction Y. For example, the fourthdirection T is rotated from the first direction X towards the seconddirection Y by an angle β. In some embodiments, the angle β ranges fromabout 0 degrees to about 180 degrees. The angle β relates to distancesD5 and D4 by formula 5.

β=ArcCos(D5/D4)  (5)

In some embodiments, the fourth direction T is equal to the firstdirection X or the second direction Y. In some embodiments, the fourthdirection T is different from the first direction X or the seconddirection Y. A center of a tile of the second set of tiles 604 isseparated from a center of an adjacent tile of the first set of tiles604 in the first direction X by a distance D5. For example, the centerof tile 608[P,1] is separated from the center of tile 608[P,2] in thefirst direction X by the distance D5.

In some embodiments, two notches (not labelled) of a tile in the secondset of tiles 604 are flush with tiles in the first set of tiles 602, andthe other two notches (not labelled) are not flush with adjacent tilesin the first set of tiles 602 or the second set of tiles 604 creating acorresponding space (not labelled) between adjacent tiles. In someembodiments, one or more spaces (not labelled) between adjacent tilescan be utilized for well contacts (not shown) or substrate contacts (notshown). In some embodiments, additional well contacts (not shown) orsubstrate contacts (not shown) can be utilized to improve latch-upprevention. In some embodiments, latch-up is a short circuit between oneor more wells and the substrate. In some embodiments, two notches (notlabelled) of a tile in the second set of tiles 604 are flush withcorresponding notches (not labelled) of two different tiles in the firstset of tiles 602. For example, notch 610 a of tile 608[2,4] of thesecond set of tiles 604 is flush with a corresponding notch 612 a oftile 608[1,Q−1] of the first set of tiles 602, and notch 610 b of tile608[2,4] of the second set of tiles 604 is flush with a correspondingnotch 612 b of tile 608[2,3] of the first set of tiles 602.

In some embodiments, two notches (not labelled for ease of illustration)of a tile in the first set of tiles 602 are flush with correspondingnotches (not labelled for ease of illustration) of two different tilesin the second set of tiles 604. For example, notch 612 b of tile608[2,3] of the first set of tiles 602 is flush with a correspondingnotch 610 b of tile 608[2,4] of the second set of tiles 604, and notch614 a of tile 608[2,3] of the first set of tiles 602 is flush with acorresponding notch 614 b of tile 608[P,2] of the second set of tiles604. In some embodiments, two notches (not labelled for ease ofillustration) of a tile in the second set of tiles 604 are not flushwith portions of adjacent tiles in the first set of tiles 602 or thesecond set of tiles 604 creating a space (not labelled for ease ofillustration) that can be utilized for well contacts (not shown) orsubstrate contacts (not shown). For example, in some embodiments, anotch 650 a of tile 608[2, 4] is not flush with adjacent tiles 608[1,4]and 608[1, 3] resulting in space 622 a. Similarly, in some embodiments,a notch 650 b of tile 608[2, 4] is not flush with adjacent tiles608[2,Q−1] and 608[P, 4] resulting in space 622 b. For example, in someembodiments, as shown in FIG. 6, space 620 a is between tile 608[2, Q−1]and tile 608[1, Q−1] of the first set of tiles 602, and space 620 b isbetween tile 608[2, Q−1] and 608[P, Q−1] of the first set of tiles 602.In these embodiments, space 622 a and space 622 b can be utilized forwell contacts (not shown) or substrate contacts (not shown). In someembodiments, two notches (not labelled for ease of illustration) of atile in the first set of tiles 602 are not flush with portions ofadjacent tiles in the second set of tiles 604 or the first set of tiles602. For example, in some embodiments, a notch 652 a of tile 608[2, Q−1]is not flush with adjacent tiles 608[2, 4] and 608[1, Q−1] resulting inspace 620 a. Similarly, in some embodiments, a notch 652 b of tile608[2, Q−1] is not flush with adjacent tiles 608[P,Q−1] and 608[2, Q]resulting in space 620 b. In these embodiments, space 620 a and space620 b can be utilized for well contacts (not shown) or substratecontacts (not shown). In some embodiments, at least space 620 a, 620 b,622 a or 622 b is 12.5% of the area of a tile in the first set of tiles602 or the second set of tiles 604.

In some embodiments, at least one of distances D1, D1′, D2, D2′, D3,D3′, D4 or D5 is different from another of distances D1, D1′, D2, D2′,D3, D3′, D4 or D5. In some embodiments, at least one of distances D1,D1′, D2, D2′, D3, D3′, D4 or D5 is the same as another of distances D1,D1′, D2, D2′, D3, D3′, D4 or D5. Other quantities or configurations ofthe first set of tiles 602 or the second set of tiles 604 are within thescope of the present disclosure. In some embodiments, each of thenotches of at least one tile of the first set of tiles 602 or the secondset of tiles 604 is a right-angled notch. In some embodiments, each ofthe notches of at least one tile of the first set of tiles 602 or thesecond set of tiles 604 is referred to as a corner notch. In someembodiments, each of the notches of at least one tile of the first setof tiles 602 or the second set of tiles 604 is a quirk. Other shapes orconfigurations of the notches in the first set of tiles 602 or thesecond set of tiles 604 are within the scope of the present disclosure.

In some embodiments, a shape of the first set of tiles 602 and a shapeof the second set of tiles 604 are non-rectangular, and therefore can beplaced as standard cells in layout design 600 closer to each other thanother designs. In some embodiments, by placing the first set of tiles602 and the second set of tiles 604 closer to each other than othercells, the first set of tiles or the second set of tiles can be utilizedto manufacture corresponding integrated circuits that are closer to eachother than other integrated circuits. In some embodiments, bymanufacturing integrated circuits that are closer to each other thanother integrated circuits, the area of the manufactured integratedcircuits are also smaller than other integrated circuits.

FIG. 7 is a diagram of a layout design 700, in accordance with someembodiments.

Layout design 700 is a variation of layout design 600 (FIG. 6). Similarelements have a same reference number increased by 100. Layout design700 combines features of layout design 300A of FIG. 3A, layout design400A of FIG. 4A and layout design 600 of FIG. 6.

Layout design 700 includes tile 708[1,2], tile 708[2,2], tile 708[1,3]and tile 708[2,3]. Tiles 708[1,2], 708[2,2], 708[1,3] and 708[2,3] are avariation of corresponding tiles 608[1,2], 608[2,2], 608[1,3] and608[2,3] of FIG. 6.

Each of tiles 708[1,2] and 708[2,2] corresponds to layout design 300A ofFIG. 3A, and each of tiles 708[1,3] and 708[2,3] corresponds to layoutdesign 400A of FIG. 4A. In some embodiments, each of tiles 708[1,2] and708[2,2] corresponds to layout design 400A of FIG. 4A, and each of tiles708[1,3] and 708[2,3] corresponds to layout design 300A of FIG. 3A. Forease of illustration, each of the elements within tiles 708[1,2],708[2,2], 708[1,3] and 708[2,3] are not labeled.

Tiles 708[1,2], 708[2,2], 708[1,3] and 708[2,3] include correspondingset of active region layout patterns 702, 704, 712 and 714.

The set of active region 702 or 704 corresponds to the set of activeregion layout patterns 412 a, 412 b, 412 c and 412 d of layout design400A. The set of active region 712 or 714 corresponds to the set ofactive region layout patterns 312 a, 312 b, 312 c and 312 d of layoutdesign 300A.

The set of active region 702 includes active region layout patterns 702a, 702 b, 702 c, 702 d, 702 e, 702 f, 702 g and 702 h. Active regionlayout pattern 702 a corresponds to active region layout patterns 404 aand 404 b, active region layout pattern 702 b corresponds to activeregion layout patterns 406 a and 406 b, active region layout pattern 702c corresponds to active region layout patterns 408 a and 408 b, activeregion layout pattern 702 d corresponds to active region layout patterns410 a and 410 b, active region layout pattern 702 e corresponds toactive region layout patterns 410 c and 410 d, active region layoutpattern 702 f corresponds to active region layout patterns 408 c and 408d, active region layout pattern 702 g corresponds to active regionlayout patterns 406 c and 406 d, active region layout pattern 702 hcorresponds to active region layout patterns 404 c and 404 d.

The set of active region 702 includes active region layout patterns 704a, 704 b, 704 c, 704 d, 704 e, 704 f, 704 g and 704 h. Active regionlayout patterns 704 a, 704 b, 704 c, 704 d, 704 e, 704 f, 704 g and 704h are similar to corresponding active region layout patterns 702 a, 702b, 702 c, 702 d, 702 e, 702 f, 702 g and 702 h, and similar detaileddescription is therefore omitted.

The set of active region 712 includes active region layout patterns 712a, 712 b, 712 c, 712 d, 712 e, 712 f, 712 g and 712 h. Active regionlayout pattern 712 a corresponds to active region layout patterns 304 aand 304 b, active region layout pattern 712 b corresponds to activeregion layout patterns 306 a and 306 b, active region layout pattern 712c corresponds to active region layout patterns 308 a and 308 b, activeregion layout pattern 712 d corresponds to active region layout patterns310 a and 310 b, active region layout pattern 712 e corresponds toactive region layout patterns 310 c and 310 d, active region layoutpattern 712 f corresponds to active region layout patterns 308 c and 308d, active region layout pattern 712 g corresponds to active regionlayout patterns 306 c and 306 d, active region layout pattern 712 hcorresponds to active region layout patterns 304 c and 304 d.

The set of active region 714 includes active region layout patterns 714a, 714 b, 714 c, 714 d, 714 e, 714 f, 714 g and 714 h. Active regionlayout patterns 714 a, 714 b, 714 c, 714 d, 714 e, 714 f, 714 g and 714h are similar to corresponding active region layout patterns 712 a, 712b, 712 c, 712 d, 712 e, 712 f, 712 g and 712 h, and similar detaileddescription is therefore omitted.

The n-type layout patterns of the set of active region layout pattern702 or 704 of corresponding tile 708[1,2] or 708[2,2] are aligned in thesecond direction Y with corresponding n-type layout patterns of the setof active region layout patterns 712 or 714 of corresponding tile708[1,3] or 708[2,3]. For example, n-type active region layout patterns702 d, 702 e, 702 h, 704 a, 704 d, 704 e and 704 h are aligned in thesecond direction Y with corresponding n-type active region layoutpatterns 712 b, 712 c, 712 f, 712 g, 714 b, 714 c and 714 f.

The p-type layout patterns of the set of active region layout pattern712 or 714 of corresponding tile 708[1,2] or 708[2,2] are aligned in thesecond direction Y with corresponding p-type layout patterns of the setof active region layout patterns 712 or 714 of corresponding tile708[1,3] or 708[2,3]. For example, p-type active region layout patterns702 c, 702 f, 702 g, 704 b, 704 c, 704 f and 704 g are aligned in thesecond direction Y with corresponding p-type active region layoutpatterns 712 a, 712 d, 712 e, 712 h, 714 a, 714 d and 714 e. Otherquantities or configurations of tiles 708[1,2], 708[2,2], 708[1,3] and708[2,3] are within the scope of the present disclosure.

In some embodiments, layout design 700 has a non-rectangular shape whichresults in a smaller standard cell than other designs. In someembodiments, by having a smaller standard cell, layout design 700 can beutilized to manufacture integrated circuits that are smaller than otherintegrated circuits.

FIG. 8 is a diagram of a layout design 800, in accordance with someembodiments.

Layout design 800 is a variation of layout design 600 of FIG. 6 andlayout design 700 of FIG. 7. Similar elements have a same referencenumber increased by 200. Layout design 800 combines features of layoutdesign 300B of FIG. 3B, layout design 400B of FIG. 4B and layout design600 of FIG. 6.

In comparison with layout design 700 of FIG. 7, layout design 800further includes a first well layout pattern 802, a second well layoutpattern 804, a third well layout pattern 806, a fourth well layoutpattern 808, a fifth well layout pattern 812, a sixth well layoutpattern 814, a seventh well layout pattern 816, an eighth well layoutpattern 818, and well layout patterns 822 a, 824 a and 828 a.

First well layout pattern 802 and fifth well layout pattern 812 aresimilar to second well layout pattern 414 of layout design 400B of FIG.4B, and similar detailed description is therefore omitted. Second welllayout pattern 804 and sixth well layout pattern 814 are similar to thefirst well layout pattern 416 of layout design 400B of FIG. 4B, andsimilar detailed description is therefore omitted. Third well layoutpattern 806 and seventh well layout pattern 816 are similar to firstwell layout pattern 314 of layout design 300B of FIG. 3B, and similardetailed description is therefore omitted. Fourth well layout pattern808 and eighth well layout pattern 818 are similar to second well layoutpattern 316 of layout design 300B of FIG. 3B, and similar detaileddescription is therefore omitted.

First well layout pattern 802 includes well layout patterns 802 a, 802 band 802 c. Well layout patterns 802 a, 802 b and 802 c are similar tocorresponding well layout patterns 454 a, 454 b and 454 c of layoutdesign 400B of FIG. 4B, and similar detailed description is thereforeomitted.

Second well layout pattern 804 includes well layout patterns 804 a, 804b, 804 c and 804 d. Well layout patterns 804 a, 804 b, 804 c and 804 dare similar to corresponding well layout patterns 456 a, 456 b, 456 cand 456 d of layout design 400B of FIG. 4B, and similar detaileddescription is therefore omitted.

Third well layout pattern 806 includes well layout patterns 806 a, 806 band 806 c. Well layout patterns 806 a, 806 b and 806 c are similar tocorresponding well layout patterns 354 a, 354 b and 354 c of layoutdesign 300B of FIG. 3B, and similar detailed description is thereforeomitted.

Fourth well layout pattern 808 includes well layout patterns 808 a and808 b. Well layout patterns 808 a and 808 b are similar to correspondingwell layout patterns 356 a and 356 b of layout design 300B of FIG. 3B,and similar detailed description is therefore omitted.

Fifth well layout pattern 812 includes well layout patterns 812 a, 812 band 812 c. Well layout patterns 812 a, 812 b and 812 c are similar tocorresponding well layout patterns 454 a, 454 b and 454 c of layoutdesign 400B of FIG. 4B, and similar detailed description is thereforeomitted.

Sixth well layout pattern 814 includes well layout patterns 814 a, 814b, 814 c and 814 d. Well layout patterns 814 a, 814 b, 814 c and 814 dare similar to corresponding well layout patterns 456 a, 456 b, 456 cand 456 d of layout design 400B of FIG. 4B, and similar detaileddescription is therefore omitted.

Seventh well layout pattern 816 includes well layout patterns 816 a, 816b and 816 c. Well layout patterns 816 a, 816 b and 816 c are similar tocorresponding well layout patterns 354 a, 354 b and 354 c of layoutdesign 300B of FIG. 3B, and similar detailed description is thereforeomitted.

Eighth well layout pattern 818 includes well layout patterns 818 a and818 b. Well layout patterns 818 a and 818 b are similar to correspondingwell layout patterns 356 a and 356 b of layout design 300B of FIG. 3B,and similar detailed description is therefore omitted.

Well layout pattern 822 a is similar to well layout pattern 456 a oflayout design 400B of FIG. 4B, and similar detailed description istherefore omitted. Well layout pattern 824 a is similar to well layoutpattern 454 a of layout design 400B of FIG. 4B, and similar detaileddescription is therefore omitted. Well layout pattern 828 a is similarto well layout pattern 356 a of layout design 300B of FIG. 3B, andsimilar detailed description is therefore omitted.

In some embodiments, well layout patterns 804 a and 828 a are part of asame continuous well layout pattern. In some embodiments, at least twoof well layout patterns 802 a, 802 b, 802 c, 806 a and 806 b are part ofa same continuous well layout pattern. In some embodiments, well layoutpatterns 804 c and 808 a are part of a same continuous well layoutpattern. In some embodiments, well layout patterns 802 c and 806 b arepart of a same continuous well layout pattern. In some embodiments, atleast two of well layout patterns 804 b, 814 a and 808 b are part of asame continuous well layout pattern.

In some embodiments, at least two of well layout patterns 812 a, 812 b,812 c, 816 a and 816 b are part of a same continuous well layoutpattern. In some embodiments, well layout patterns 814 c and 818 a arepart of a same continuous well layout pattern. In some embodiments, welllayout patterns 812 c and 816 b are part of a same continuous welllayout pattern. In some embodiments, at least two of well layoutpatterns 822 a, 814 b and 818 b are part of a same continuous welllayout pattern. In some embodiments, well layout patterns 816 c and 824a are part of a same continuous well layout pattern.

Other quantities or configurations of one or more of first well layoutpattern 802, second well layout pattern 804, third well layout pattern806, fourth well layout pattern 808, fifth well layout pattern 812,sixth well layout pattern 814, seventh well layout pattern 816, eighthwell layout pattern 818 or well layout patterns 822 a, 824 a and 828 aare within the scope of the present disclosure.

In some embodiments, layout design 800 has a non-rectangular shape whichresults in a smaller standard cell than other designs. In someembodiments, by having a smaller standard cell, layout design 800 can beutilized to manufacture integrated circuits that are smaller than otherintegrated circuits.

FIG. 9 is a flowchart of a method 900 of forming or manufacturing amemory cell array in accordance with some embodiments. It is understoodthat additional operations may be performed before, during, and/or afterthe method 900 depicted in FIG. 9, and that some other processes mayonly be briefly described herein. In some embodiments, the method 900 isusable to form one or more memory cells, such as memory cell 100 (FIG.1), one or more memory cell arrays, such as memory cell array 200A-200B(FIGS. 2A-2B) or one or more integrated circuits such as integratedcircuit 500A-500H (FIGS. 5A-5H). In some embodiments, the method 900 isusable to form memory cell arrays or integrated circuits having similarstructural relationships as one or more of layout designs 300A-300B,400A-400B or 600-800 (FIGS. 3A-3B, 4A-4B or 6-8).

In operation 902 of method 900, a first set of tiles 602 extending in afirst direction (e.g., third direction S) is generated. In someembodiments, generating the first set of tiles 602 of operation 902includes operation 902 a.

In some embodiments, operation 902 a includes generating a first layoutdesign (e.g., layout design 300A-300B) of a first set of memory cells204. In some embodiments, at least one tile of the first set of tiles602 corresponds to layout design 300A or 300B. In some embodiments, eachtile of the first set of tiles 602 corresponds to layout design 300A or300B of the first set of memory cells 204. In some embodiments, eachtile of the first set of tiles 602 is offset from an adjacent tile ofthe first set of tiles in the second direction Y different from thefirst direction ((e.g., third direction S).

In some embodiments, generating the first layout design (e.g., layoutdesign 300A-300B) of the first set of memory cells 204 of operation 902a includes generating a first portion 302 a of the first layout design(e.g., layout design 300A-300B), generating a second portion 302 b ofthe first layout design, generating a third portion 302 c of the firstlayout design and generating a fourth portion 302 d of the first layoutdesign.

In some embodiments, the first portion 302 a of the first layout design(e.g., layout design 300A-300B) corresponds to fabricating a firstmemory cell 202[1,2] of the first set of memory cells 204 of memory cellarray 200A-200B. In some embodiments, the second portion 302 b of thefirst layout design (e.g., layout design 300A-300B) corresponds tofabricating a second memory cell 202[2,2] of the first set of memorycells 204 of memory cell array 200A-200B. In some embodiments, the thirdportion 302 c of the first layout design (e.g., layout design 300A-300B)corresponds to fabricating a third memory cell 202[1,3] of the first setof memory cells 204 of memory cell array 200A-200B. In some embodiments,the fourth portion 302 d of the first layout design (e.g., layout design300A-300B) corresponds to fabricating a fourth memory cell 202[2,3] ofthe first set of memory cells 204 of memory cell array 200A-200B.

In some embodiments, the first portion 302 a of the first layout design(e.g., layout design 300A-300B) and the second portion 302 b of thefirst layout design are mirror images of each other with respect to thesecond direction Y. In some embodiments, the third portion 302 c of thefirst layout design (e.g., layout design 300A-300B) and the fourthportion 302 d of the first layout design are mirror images of each otherwith respect to the second direction Y.

In operation 904 of method 900, a second set of tiles 604 extending inthe first direction (e.g., third direction S) is generated. In someembodiments, the second set of tiles 604 is separated from the first setof tiles 602 in at least the second direction Y. In some embodiments,generating the second set of tiles 604 of operation 904 includesoperation 904 a.

In some embodiments, operation 904 a includes generating a second layoutdesign (e.g., layout design 400A-400B) of a second set of memory cells206. In some embodiments, at least one tile of the second set of tiles604 corresponds to layout design 400A or 400B. In some embodiments, eachtile of the second set of tiles 604 corresponds to the second layoutdesign (e.g., layout design 400A-400B) of the second set of memory cells206. In some embodiments, each tile of the second set of tiles 604 isoffset from an adjacent tile of the second set of tiles 604 in thesecond direction Y.

In some embodiments, generating the second layout design (e.g., layoutdesign 400A-400B) of the second set of memory cells 206 of operation 904a includes generating a first portion 402 a of the second layout design(e.g., layout design 400A-400B), generating a second portion 402 b ofthe first layout design, generating a third portion 402 c of the firstlayout design and generating a fourth portion 402 d of the first layoutdesign.

In some embodiments, the first portion 402 a of the second layout design(e.g., layout design 400A-400B) corresponds to fabricating a firstmemory cell 202[2,4] of the second set of memory cells 206 of memorycell array 200A-200B. In some embodiments, the second portion 402 b ofthe second layout design (e.g., layout design 400A-400B) corresponds tofabricating a second memory cell 202[3,4] of the second set of memorycells 206 of memory cell array 200A-200B. In some embodiments, the thirdportion 402 c of the second layout design (e.g., layout design400A-400B) corresponds to fabricating a third memory cell 202[2,5] ofthe second set of memory cells 206 of memory cell array 200A-200B. Insome embodiments, the fourth portion 402 d of the second layout design(e.g., layout design 400A-400B) corresponds to fabricating a fourthmemory cell 202[3,5] of the second set of memory cells 206 of memorycell array 200A-200B.

In some embodiments, the first portion 402 a of the second layout design(e.g., layout design 400A-400B) and the third portion 402 c of thesecond layout design are mirror images of each other with respect to thethird direction (e.g., first direction X). In some embodiments, thesecond portion 402 b of the second layout design (e.g., layout design400A-400B) and the fourth portion 402 d of the second layout design aremirror images of each other with respect to the third direction (e.g.,first direction X).

In some embodiments, the first set of tiles 602 and the second set oftiles 604 alternate with each other in the second direction X. In someembodiments, each tile of the first set of tiles 602 and each tile ofthe second set of tiles 604 extends in a third direction (e.g., firstdirection X) different from the first direction and the seconddirection.

In some embodiments, at least operation 902 or 904 is performed by aprocessing device (e.g., processor 1202 (FIG. 12)) configured to executeinstructions for generating the first set of tiles 602 or the second setof tiles 604. In some embodiments, the first set of tiles 602 or thesecond set of tiles 604 are stored in a memory (e.g., a non-transitorycomputer-readable medium 1204 (FIG. 12)) as layout design 1216.

In some embodiments, at least layout design 300A-300B, 400A-400B or600-800 is a graphic database system (GDSII) file format.

In operation 906 of method 900, a memory cell array 200A or 200B or anintegrated circuit 500A or 500B is manufactured based on at least thefirst layout design (layout design 300A or 300B), the second layoutdesign (second layout design 400A or 400B) or layout designs 600-800. Insome embodiments, operation 906 of method 900 includes manufacturingmemory cell array 200A or 200B or integrated circuit 500A or 500B basedon at least the first set of tiles 602 or the second set of tiles 604.In some embodiments, operation 906 includes manufacturing memory cell100 based on at least the first layout design 300A or 300B or secondlayout design 400A or 400B. In some embodiments, operation 906 includesmanufacturing memory cell array 200A or 200B or integrated circuit 500Aor 500B based on at least the first set of tiles 602 or the second setof tiles 604.

In some embodiments, operation 906 of method 900 comprises manufacturingat least one mask based on at least layout design 300A-300B, 400A-400Bor 600-800, and manufacturing the memory cell array (e.g., memory cell,100, memory cell array 200A-200B) or integrated circuit (e.g.,integrated circuit 500A or 500B) based on the at least one mask.

In some embodiments, one or more of operations 902, 904 or 906 is notperformed.

In some embodiments, method 900 generates one or more layout designs(e.g., first layout design 300A-300B, second layout design 400A-400B orlayout design 600-800) that occupy less area than other approaches. Insome embodiments, method 900 is used to manufacture a memory cell array(e.g., memory cell 100, memory cell array 200A-200B or integratedcircuit 500A-500B) that occupies less area than other memory cellarrays.

FIGS. 10A-10B are a flowchart of a method 1000 of generating a layoutdesign of a memory cell array in accordance with some embodiments. It isunderstood that additional operations may be performed before, during,and/or after the method 1000 depicted in FIGS. 10A-10B, and that someother processes may only be briefly described herein. Method 1000 is anembodiment of at least operation 902 a or 904 a. In some embodiments,the method 1000 is usable to generate one or more of layout designs300A-300B (FIGS. 3A-3B) or 400A-400B (FIGS. 4A-4B) or 600-700 (FIGS.600-700) of memory cell 100 (FIG. 1), memory cell array 200A-200B (FIGS.2A-2B) or integrated circuit 500A-500B (FIGS. 5A-5H).

In operation 1002 of method 1000, a set of active region layout patterns312 a or 412 a is generated. In some embodiments, generating the set ofactive region layout patterns 312 a, 412 a corresponds to fabricating aset of active regions 504 or 505 of memory cell array 200A-200B. In someembodiments, each of the layout patterns of the set of active regionlayout patterns 312 a, 412 a is separated from an adjacent layoutpattern of the set of active region layout patterns 312 a, 412 a in thefirst direction X by a first pitch. In some embodiments, the set ofactive region layout patterns 312 a, 412 a extend in the seconddirection Y different from the first direction and being located on afirst layout level (e.g., active region or well).

In some embodiments, the set of active region layout patterns of method1000 includes one or more of set of active region layout patterns 312 b,312 c, 312 d, 412 a, 412 b or 412 c.

In some embodiments, generating the set of active region layout patterns312 a, 412 a of operation 1002 includes generating a first active regionlayout pattern 304 a, 404 a adjacent to a first side 352 a, 452 a of thelayout design 300A-300B or 400A-400B of memory cell 100, and generatinga second active region layout pattern 310 a, 410 a adjacent to a secondside 352 b 1, 452 b 1 of memory cell 100 opposite from the first side352 a, 452 a of the memory cell 100. In some embodiments, a length ofthe first active region layout pattern 304 a, 404 a in the seconddirection Y is different from a length of the second active regionlayout pattern 310 a, 410 a in the second direction Y.

In operation 1004, a set of active region layout patterns 312 a, 412 ais placed on a first layout level. In some embodiments, the first layoutlevel corresponds to the active region of layout design 300A-300B or400A-400B (FIGS. 4A-4B).

In operation 1006, a set of gate layout patterns 326 a or 426 a isgenerated. In some embodiments, the set of gate layout patterns 326 a,426 a corresponds to fabricating a set of gate structures 527 of memorycell array 200A-200B or integrated circuit 500A-500B. In someembodiments, the set of gate layout patterns 326 a, 426 a extends in thefirst direction X and overlaps the set of active region layout patterns312 a, 412 a.

In some embodiments, the set of gate layout patterns of method 1000includes one or more of set of gate layout patterns 326 b, 326 c, 326 d,426 b, 426 c or 426 d.

In operation 1008, the set of gate layout patterns 326 a, 426 a isplaced on a second layout level (e.g., POLY) different from the firstlayout level.

In operation 1010, a first set of conductive feature layout patterns 338a or 438 a is generated. In some embodiments, the first set ofconductive feature layout patterns 338 a, 438 a corresponds tofabricating a first set of conductive structures 538 of memory cellarray 200A-200B or integrated circuit 500A-500B. In some embodiments,the first set of conductive feature layout patterns 338 a, 438 a extendsin the first direction X, and is over at least the set of active regionlayout patterns 312 a, 412 a or the set of gate layout patterns 326 a,426 a. In some embodiments, each conductive feature layout pattern ofthe first set of conductive feature layout patterns 338 a, 438 a isseparated from an adjacent layout pattern of the first set of conductivefeature layout patterns 338 a, 438 a in at least the first direction Xor the second direction Y.

In some embodiments, the first set of conductive feature layout patternsof method 1000 includes one or more of set of conductive feature layoutpatterns 338 b, 338 c, 338 d, 340, 342, 344, 438 b, 438 c, 438 d, 440,442 or 444.

In operation 1012, the first set of conductive feature layout patterns338 a, 438 a is placed on a third layout level (e.g., M1) different fromthe first layout level and the second layout level.

In operation 1014, a second set of conductive feature layout patterns350 or 450 is generated. In some embodiments, the second set ofconductive feature layout patterns 350, 450 corresponds to fabricating asecond set of conductive structures 552 of memory cell array 200A-200Bor integrated circuit 500A-500B. In some embodiments, the second set ofconductive feature layout patterns 350, 450 extends in the firstdirection X and overlaps at least the second active region layoutpattern 310 a, 310 b, 310 c, 310 d, 410 a, 410 b, 410 c or 410 d and thesecond side 352 b 1, 452 b 1 of layout design 300A-300 b, 400A-400B ofmemory cell 100. In some embodiments, each conductive feature layoutpattern of the second set of conductive feature layout patterns 350, 450is separated from an adjacent layout pattern of the second set ofconductive feature layout patterns 350, 450 in at least the firstdirection X or the second direction Y.

In operation 1016, the second set of conductive feature layout patterns350, 450 is placed on a fourth layout level (e.g., M2) different fromthe first layout level, the second layout level and the third layoutlevel.

In operation 1018, a first set of via layout patterns 358 a or 458 a isgenerated. In some embodiments, the first set of via layout patterns 358a, 458 a corresponds to fabricating a first set of vias 572. In someembodiments, the first set of vias 572 couple the first set ofconductive structures 538 to the set of active regions 504, 505. In someembodiments, each via layout pattern of the first set of via layoutpatterns 358 a, 458 a is located where each conductive feature layoutpattern of the first set of conductive feature layout patterns 338 a,438 a overlaps each active region layout pattern of the set of activeregion layout patterns 312 a, 412 a.

In some embodiments, the first set of via layout patterns of method 1000includes one or more of via layout patterns 358 b, 358 c, 358 d, 458 b,458 c, 458 d, 374, 376, 378, 380, 474, 476, 478 or 480.

In operation 1020, the first set of via layout patterns 358 a, 458 a isplaced between the first set of conductive feature layout patterns 338a, 438 a and the set of active region layout patterns 312 a, 412 a. Insome embodiments, the first set of via layout patterns 358 a, 458 a areon at least the V0 level of layout design 300A-300B, 400A-400B.

In operation 1022, a second set of via layout patterns 380 or 480 isgenerated. In some embodiments, the second set of via layout patterns380, 480 corresponds to fabricating a second set of vias 523. In someembodiments, the second set of vias 523 couple the first set ofconductive structures 338 a, 438 a to the set of gates 527. In someembodiments, a first via layout pattern 380 a, 480 a of the second setof via layout patterns 380, 480 is located where a first conductivefeature layout pattern 340 a, 440 a of the set of conductive featurelayout patterns 340, 440 overlaps a first gate layout pattern 324 a, 324c, 424 a, 424 c of the set of gate layout patterns 326 a, 426 a.

In some embodiments, the second set of via layout patterns of method1000 includes one or more of via layout patterns 358 a, 358 b, 358 c,358 d, 458 a, 458 b, 458 c, 458 d, 374, 376, 378, 474, 476 or 478.

In operation 1024, the second set of via layout patterns 380, 480 isplaced between the first set of conductive feature layout patterns 340,440 and the set of gate layout patterns 326 a, 426 a. In someembodiments, the second set of via layout patterns 380, 480 are on atleast the VG level of layout design 300A-300B, 400A-400B

Method 1000 includes either operations 1026-1032 or operations1026′-1032′.

Operations 1026-1032 are discussed with reference to layout design300A-300B.

For example, first well layout pattern 314 corresponds to the first welllayout pattern of operations 1026-1032, and the second well layoutpattern 316 corresponds to the second well layout pattern of operations1026-1032 of layout design 300A-300B.

Operations 1026′-1032′ are discussed with reference to layout design400A-400B, such that first well layout pattern 416 corresponds to thefirst well layout pattern of operations 1026′-1032′, and the second welllayout pattern 414 corresponds to the second well layout pattern ofoperations 1026′-1032′.

For simplicity, operations 1026′-1032′ are discussed after thediscussion of operations 1026-1032.

In operation 1026, a first well layout pattern 314 is generated. In someembodiments, the first well layout pattern 314 corresponds tofabricating a first well 501 of memory cell array 200A-200B orintegrated circuit 500A. In some embodiments, the first well 501 has afirst dopant type. In some embodiments, the first dopant type is anN-dopant type. In some embodiments, the first dopant type is a P-dopanttype.

In some embodiments, operation 1026 includes one or more of operations1026 a or 1026 b.

In some embodiments, operation 1026 a includes generating a first layoutpattern (e.g., layout pattern 354 a or 354 c). In some embodiments, thefirst layout pattern 354 a corresponds to fabricating a first portion501 a of the first well 501. In some embodiments, the first layoutpattern 354 a extends in the second direction Y and is adjacent to thefirst side 352 a of the layout design 300B of memory cell 100.

In some embodiments, operation 1026 b includes generating a secondlayout pattern (e.g., layout pattern 354 b). In some embodiments, thesecond layout pattern 354 b corresponds to fabricating a second portion501 b of the first well 501. In some embodiments, the second layoutpattern extends in the second direction and is adjacent to the secondside of the memory cell 100.

In operation 1028, the first well layout pattern 314 is placed on afourth layout level (e.g., well level) different from the first layoutlevel, the second layout level and the third layout level. In someembodiments, a portion of the fourth layout level includes the firstlayout level. In some embodiments, a portion of the fourth layout levelis the same as the first layout level.

In some embodiments, operation 1028 includes one or more of operations1028 a or 1028 b.

In some embodiments, operation 1028 a includes placing the first layoutpattern 354 a below the first active region layout pattern 304 a.

In some embodiments, operation 1028 b includes placing the second layoutpattern 354 b below the second active region layout pattern 310 a.

In operation 1030, a second well layout pattern 316 is generated. Insome embodiments, the second well layout pattern 316 corresponds tofabricating a second well 501′ of memory cell array 200A-200B orintegrated circuit 500A. In some embodiments, the second well 501′ has asecond dopant type different from the first dopant type. In someembodiments, the second dopant type is a P-dopant type. In someembodiments, the second dopant type is an N-dopant type.

In some embodiments, operation 1030 includes one or more of operations1030 a or 1030 b.

In some embodiments, operation 1030 a includes generating a third layoutpattern (e.g., layout pattern 356 a). In some embodiments, the thirdlayout pattern 356 a corresponds to fabricating a portion 501 c of thesecond well 501′. In some embodiments, the third layout pattern 356 aextends in the second direction Y. In some embodiments, the third layoutpattern 356 a is between the first layout pattern and 354 a the secondlayout pattern 354 b.

In some embodiments, operation 1030 b includes generating a fourthlayout pattern (e.g., layout pattern 356 b). In some embodiments, thefourth layout pattern 356 b corresponds to fabricating a portion of thesecond well 501′ similar to portion 501 c. In some embodiments, thefourth layout pattern 356 b extends in the second direction Y. In someembodiments, the fourth layout pattern 356 b is between the secondlayout pattern 354 b and the third layout pattern 354 c.

In operation 1032, the second well layout pattern 316 is placed on thefourth layout level. In some embodiments, operation 1032 furtherincludes placing the second well layout pattern 316 between the firstlayout pattern 354 a and the second layout pattern 354 b. In someembodiments, operation 1032 further includes placing the second welllayout pattern 316 below a third active region layout pattern 306 a ofthe set of active region layout patterns 312 a and a fourth activeregion 308 a of the set of active region layout patterns 312 a.

In some embodiments, operation 1032 includes one or more of operations1032 a or 1032 b.

In some embodiments, operation 1032 a includes placing the third layoutpattern 356 a below each of a third active region layout pattern 306 aof the set of active region layout patterns 312 a and a fourth activeregion 308 a of the set of active region layout patterns 312 a.

In some embodiments, operation 1032 b includes placing the fourth layoutpattern 356 b below each of active region layout pattern 306 b of theset of active region layout patterns 312 a and active region 308 b ofthe set of active region layout patterns 312 a.

For simplicity, operations 1026′-1032′ are discussed after thediscussion of operations 1026-1032.

In operation 1026′, a first well layout pattern 416 is generated. Insome embodiments, the first well layout pattern 416 corresponds tofabricating a first well 502 of memory cell array 200A-200B orintegrated circuit 500B. In some embodiments, the first well 502 has afirst dopant type. In some embodiments, the first dopant type is aP-dopant type. In some embodiments, the first dopant type is an N-dopanttype.

In some embodiments, operation 1026′ includes one or more of operations1026 a′ or 1026 b′.

In some embodiments, operation 1026 a′ includes generating a firstlayout pattern (e.g., layout pattern 456 a or 456 b). In someembodiments, the first layout pattern 456 a corresponds to fabricating afirst portion 502 a of the first well 502. In some embodiments, thefirst layout pattern 456 a extends in the second direction Y and isadjacent to the first side 452 a of the layout design 400B of memorycell 100.

In some embodiments, operation 1026 b′ includes generating a secondlayout pattern (e.g., layout pattern 456 c or 456 d). In someembodiments, the second layout pattern 456 c corresponds to fabricatinga second portion 502 b of the first well 501. In some embodiments, thesecond layout pattern 456 c extends in the second direction Y and isadjacent to the second side 452 b 1 of the layout design 400B of memorycell 100.

In operation 1028′, the first well layout pattern 416 is placed on thefourth layout level. In some embodiments, operation 1028′ includes oneor more of operations 1028 a′ or 1028 b′.

In some embodiments, operation 1028 a′ includes placing the first layoutpattern 456 a below the first active region layout pattern 404 a.

In some embodiments, operation 1028 b′ includes placing the secondlayout pattern 456 c below a first portion 410 a 1 of the second activeregion layout pattern 410 a.

In operation 1030′, a second well layout pattern 414 is generated. Insome embodiments, the second well layout pattern 414 corresponds tofabricating a second well 502′ of memory cell array 200A-200B orintegrated circuit 500B. In some embodiments, the second well 502′ has asecond dopant type different from the first dopant type. In someembodiments, the second dopant type is an N-dopant type. In someembodiments, the second dopant type is a P-dopant type.

In some embodiments, operation 1030′ includes one or more of operations1030 a′ or 1030 b′.

In some embodiments, operation 1030 a′ includes generating a thirdlayout pattern (e.g., layout pattern 454 a or 454 c). In someembodiments, the third layout pattern 454 a corresponds to fabricating afirst portion 502 c of the second well 502′. In some embodiments, thethird layout pattern 454 a extends in the second direction Y.

In some embodiments, operation 1030 b′ includes generating a fourthlayout pattern (e.g., layout pattern 454 b). In some embodiments, thefourth layout pattern 454 b corresponds to fabricating a second portion502 d of the second well 502′. In some embodiments, the fourth layoutpattern 454 b extends in the second direction Y and is adjacent to thesecond side 452 b 1 of the layout design 400B of memory cell 100.

In operation 1032′, the second well layout pattern 414 is placed on thefourth layout level.

In some embodiments, operation 1032′ includes one or more of operations1032 a′ or 1032 b′.

In some embodiments, operation 1032 a′ includes placing the third layoutpattern 454 a between the first layout pattern 456 a and at least thesecond layout pattern 456 c or the fourth layout pattern 456 d. In someembodiments, operation 1032 a′ includes placing the third layout pattern454 a below a third active region layout pattern 406 a of the set ofactive region layout patterns 412 a and a fourth active region 408 a ofthe set of active region layout patterns 412 a.

In some embodiments, operation 1032 b′ includes placing the fourthlayout pattern 454 b below a second portion 410 a 2 of the second activeregion layout pattern 410 a.

In some embodiments, one or more of operations 1002-1024, 1026-1032 or1026′-1032′ is not performed.

One or more of the operations of methods 1000 is performed by aprocessing device (e.g., processor 1202 (FIG. 12)) configured to executeinstructions for generating a layout design (e.g., first layout design300A-300B, second layout design 400A-400B or layout design 600-800). Insome embodiments, first layout design 300A-300B, second layout design400A-400B or layout design 600-800 are stored in a memory (e.g., anon-transitory computer-readable medium 1204 (FIG. 12)) as layout design1216. In some embodiments, one or more operations of methods 900-1000 isperformed using a same processing device as that used in a different oneor more operations of methods 900-1000. In some embodiments, a differentprocessing device is used to perform one or more operations of methods900-1000 from that used to perform a different one or more operations ofmethods 900-1000.

In some embodiments, method 1000 generates one or more layout designs(e.g., first layout design 300A-300B, second layout design 400A-400B orlayout design 600-800) that occupy less area than other approaches.

FIG. 11 is a block diagram of an integrated circuit (IC) manufacturingsystem 1100, and an IC manufacturing flow associated therewith, inaccordance with at least one embodiment of the present disclosure.

In FIG. 11, IC manufacturing system 1100 includes entities, such as adesign house 1120, a mask house 1130, and an IC manufacturer/fabricator(“fab”) 1140, that interact with one another in the design, development,and manufacturing cycles and/or services related to manufacturing an ICdevice 1160. The entities in system 1100 are connected by acommunications network. In some embodiments, the communications networkis a single network. In some embodiments, the communications network isa variety of different networks, such as an intranet and the Internet.The communications network includes wired and/or wireless communicationchannels. Each entity interacts with one or more of the other entitiesand provides services to and/or receives services from one or more ofthe other entities. In some embodiments, two or more of design house1120, mask house 1130, and IC fab 1140 is owned by a single largercompany. In some embodiments, two or more of design house 1120, maskhouse 1130, and IC fab 1140 coexist in a common facility and use commonresources.

Design house (or design team) 1120 generates an IC design layout 1122.IC design layout 1122 includes various geometrical patterns designed foran IC device 1160. The geometrical patterns correspond to patterns ofmetal, oxide, or semiconductor layers that make up the variouscomponents of IC device 1160 to be fabricated. The various layerscombine to form various IC features. For example, a portion of IC designlayout 1122 includes various IC features, such as an active region, gateelectrode, source electrode and drain electrode, metal lines or vias ofan interlayer interconnection, and openings for bonding pads, to beformed in a semiconductor substrate (such as a silicon wafer) andvarious material layers disposed on the semiconductor substrate. Designhouse 1120 implements a proper design procedure to form IC design layout1122. The design procedure includes one or more of logic design,physical design or place and route. IC design layout 1122 is presentedin one or more data files having information of the geometricalpatterns. For example, IC design layout 1122 can be expressed in a GDSIIfile format or DFII file format.

Mask house 1130 includes data preparation 1132 and mask fabrication1134. Mask house 1130 uses IC design layout 1122 to manufacture one ormore masks to be used for fabricating the various layers of IC device1160 according to IC design layout 1122. Mask house 1130 performs maskdata preparation 1132, where IC design layout 1122 is translated into arepresentative data file (“RDF”). Mask data preparation 1132 providesthe RDF to mask fabrication 1134. Mask fabrication 1134 includes a maskwriter. A mask writer converts the RDF to an image on a substrate, suchas a mask (reticle) or a semiconductor wafer. The IC design layout 1122is manipulated by mask data preparation 1132 to comply with particularcharacteristics of the mask writer and/or requirements of IC fab 1140.In FIG. 11, mask data preparation 1132 and mask fabrication 1134 areillustrated as separate elements. In some embodiments, mask datapreparation 1132 and mask fabrication 1134 can be collectively referredto as mask data preparation.

In some embodiments, mask data preparation 1132 includes opticalproximity correction (OPC) which uses lithography enhancement techniquesto compensate for image errors, such as those that can arise fromdiffraction, interference, other process effects and the like. OPCadjusts IC design layout 1122. In some embodiments, mask datapreparation 1132 includes further resolution enhancement techniques(RET), such as off-axis illumination, sub-resolution assist features,phase-shifting masks, other suitable techniques, and the like orcombinations thereof. In some embodiments, inverse lithographytechnology (ILT) is also used, which treats OPC as an inverse imagingproblem.

In some embodiments, mask data preparation 1132 includes a mask rulechecker (MRC) that checks the IC design layout that has undergoneprocesses in OPC with a set of mask creation rules which contain certaingeometric and/or connectivity restrictions to ensure sufficient margins,to account for variability in semiconductor manufacturing processes, andthe like. In some embodiments, the MRC modifies the IC design layout1122 to compensate for limitations during mask fabrication 1134, whichmay undo part of the modifications performed by OPC in order to meetmask creation rules.

In some embodiments, mask data preparation 1132 includes lithographyprocess checking (LPC) that simulates processing that will beimplemented by IC fab 1140 to fabricate IC device 1160. LPC simulatesthis processing based on IC design layout 1122 to create a simulatedmanufactured device, such as IC device 1160. The processing parametersin LPC simulation can include parameters associated with variousprocesses of the IC manufacturing cycle, parameters associated withtools used for manufacturing the IC, and/or other aspects of themanufacturing process. LPC takes into account various factors, such asaerial image contrast, depth of focus (“DOF”), mask error enhancementfactor (“MEEF”), other suitable factors, and the like or combinationsthereof. In some embodiments, after a simulated manufactured device hasbeen created by LPC, if the simulated device is not close enough inshape to satisfy design rules, OPC and/or MRC are be repeated to furtherrefine IC design layout 1122.

It should be understood that the above description of mask datapreparation 1132 has been simplified for the purposes of clarity. Insome embodiments, data preparation 1132 includes additional featuressuch as a logic operation (LOP) to modify the IC design layout 1122according to manufacturing rules. Additionally, the processes applied toIC design layout 1122 during data preparation 1132 may be executed in avariety of different orders.

After mask data preparation 1132 and during mask fabrication 1134, amask or a group of masks are fabricated based on the modified IC designlayout. In some embodiments, an electron-beam (e-beam) or a mechanism ofmultiple e-beams is used to form a pattern on a mask (photomask orreticle) based on the modified IC design layout. The mask can be formedin various technologies. In some embodiments, the mask is formed usingbinary technology. In some embodiments, a mask pattern includes opaqueregions and transparent regions. A radiation beam, such as anultraviolet (UV) beam, used to expose the image sensitive material layer(e.g., photoresist) which has been coated on a wafer, is blocked by theopaque region and transmits through the transparent regions. In oneexample, a binary mask includes a transparent substrate (e.g., fusedquartz) and an opaque material (e.g., chromium) coated in the opaqueregions of the mask. In another example, the mask is formed using aphase shift technology. In the phase shift mask (PSM), various featuresin the pattern formed on the mask are configured to have proper phasedifference to enhance the resolution and imaging quality. In variousexamples, the phase shift mask can be attenuated PSM or alternating PSM.The mask(s) generated by mask fabrication 1134 is used in a variety ofprocesses. For example, such a mask(s) is used in an ion implantationprocess to form various doped regions in the semiconductor wafer, in anetching process to form various etching regions in the semiconductorwafer, and/or in other suitable processes.

IC fab 1140 is an IC fabrication business that includes one or moremanufacturing facilities for the fabrication of a variety of differentIC products. In some embodiments, IC Fab 1140 is a semiconductorfoundry. For example, there may be a manufacturing facility for thefront end fabrication of a plurality of IC products (front-end-of-line(FEOL) fabrication), while a second manufacturing facility may providethe back end fabrication for the interconnection and packaging of the ICproducts (back-end-of-line (BEOL) fabrication), and a thirdmanufacturing facility may provide other services for the foundrybusiness.

IC fab 1140 uses the mask (or masks) fabricated by mask house 1130 tofabricate IC device 1160. Thus, IC fab 1140 at least indirectly uses ICdesign layout 1122 to fabricate IC device 1160. In some embodiments, asemiconductor wafer 1142 is fabricated by IC fab 1140 using the mask (ormasks) to form IC device 1160. Semiconductor wafer 1142 includes asilicon substrate or other proper substrate having material layersformed thereon. Semiconductor wafer further includes one or more ofvarious doped regions, dielectric features, multilevel interconnects,and the like (formed at subsequent manufacturing steps).

Details regarding an integrated circuit (IC) manufacturing system (e.g.,system 1100 of FIG. 11), and an IC manufacturing flow associatedtherewith are found, e.g., in U.S. Pat. No. 9,256,709, granted Feb. 9,2016, U.S. Pre-Grant Publication No. 20150278429, published Oct. 1,2015, U.S. Pre-Grant Publication No. 20140040838, published Feb. 6,2014, and U.S. Pat. No. 7,260,442, granted Aug. 21, 2007, the entiretiesof each of which are hereby incorporated by reference.

FIG. 12 is a block diagram of a system 1200 for designing an IC layoutdesign in accordance with some embodiments. In some embodiments, system1200 generates or places one or more IC layout designs described herein.System 1200 includes a hardware processor 1202 and a non-transitory,computer readable storage medium 1204 encoded with, i.e., storing, thecomputer program code 1206, i.e., a set of executable instructions.Computer readable storage medium 1204 is configured for interfacing withmanufacturing machines for producing the integrated circuit (e.g.,memory cell array). The processor 1202 is electrically coupled to thecomputer readable storage medium 1204 via a bus 1208. The processor 1202is also electrically coupled to an I/O interface 1210 by bus 1208. Anetwork interface 1212 is also electrically connected to the processor1202 via bus 1208. Network interface 1212 is connected to a network1214, so that processor 1202 and computer readable storage medium 1204are capable of connecting to external elements via network 1214. Theprocessor 1202 is configured to execute the computer program code 1206encoded in the computer readable storage medium 1204 in order to causesystem 1200 to be usable for performing a portion or all of theoperations as described in method 900 or 1000.

In some embodiments, the processor 1202 is a central processing unit(CPU), a multi-processor, a distributed processing system, anapplication specific integrated circuit (ASIC), and/or a suitableprocessing unit.

In some embodiments, the computer readable storage medium 1204 is anelectronic, magnetic, optical, electromagnetic, infrared, and/or asemiconductor system (or apparatus or device). For example, the computerreadable storage medium 1204 includes a semiconductor or solid-statememory, a magnetic tape, a removable computer diskette, a random accessmemory (RAM), a read-only memory (ROM), a rigid magnetic disk, and/or anoptical disk. In some embodiments using optical disks, the computerreadable storage medium 1204 includes a compact disk-read only memory(CD-ROM), a compact disk-read/write (CD-R/W), and/or a digital videodisc (DVD).

In some embodiments, the storage medium 1204 stores the computer programcode 1206 configured to cause system 1200 to perform method 900 or 1000.In some embodiments, the storage medium 1204 also stores informationneeded for performing method 900 or 1000 as well as informationgenerated during performing method 900 or 1000, such as layout design1216 and user interface 1218, and/or a set of executable instructions toperform the operation of method 900 or 1000. In some embodiments, layoutdesign 1216 comprises one or more of layout designs 300A, 300B, 400A,400B or 600-800.

In some embodiments, the storage medium 1204 stores instructions (e.g.,computer program code 1206) for interfacing with manufacturing machines.The instructions (e.g., computer program code 1206) enable processor1202 to generate manufacturing instructions readable by themanufacturing machines to effectively implement method 900 or 1000during a manufacturing process.

System 1200 includes I/O interface 1210. I/O interface 1210 is coupledto external circuitry. In some embodiments, I/O interface 1210 includesa keyboard, keypad, mouse, trackball, trackpad, and/or cursor directionkeys for communicating information and commands to processor 1202.

System 1200 also includes network interface 1212 coupled to theprocessor 1202. Network interface 1212 allows system 1200 to communicatewith network 1214, to which one or more other computer systems areconnected. Network interface 1212 includes wireless network interfacessuch as BLUETOOTH, WIFI, WIMAX, GPRS, or WCDMA; or wired networkinterface such as ETHERNET, USB, or IEEE-1394. In some embodiments,method 900 or 1000 is implemented in two or more systems 1200, andinformation such as layout design, and user interface are exchangedbetween different systems 1200 by network 1214.

System 1200 is configured to receive information related to a layoutdesign through I/O interface 1210 or network interface 1212. Theinformation is transferred to processor 1202 by bus 1208 to determine alayout design for producing one or more of memory cell 100, memory cellarray 200A or 200B or memory cell array 500A or 500B. The layout designis then stored in computer readable medium 1204 as layout design 1216.System 1200 is configured to receive information related to a userinterface through I/O interface 1210 or network interface 1212. Theinformation is stored in computer readable medium 1204 as user interface1218.

In some embodiments, method 900 or 1000 is implemented as a standalonesoftware application for execution by a processor. In some embodiments,method 900 or 1000 is implemented as a software application that is apart of an additional software application. In some embodiments, method900 or 1000 is implemented as a plug-in to a software application. Insome embodiments, method 900 or 1000 is implemented as a softwareapplication that is a portion of an EDA tool. In some embodiments,method 900 or 1000 is implemented as a software application that is usedby an EDA tool. In some embodiments, the EDA tool is used to generate alayout of the integrated circuit device or memory cell array. In someembodiments, the layout is stored on a non-transitory computer readablemedium. In some embodiments, the layout is generated using a tool suchas VIRTUOSO® available from CADENCE DESIGN SYSTEMS, Inc., or anothersuitable layout generating tool. In some embodiments, the layout isgenerated based on a netlist which is created based on the schematicdesign. In some embodiments, method 900 or 1000 is implemented by amanufacturing device to manufacture an integrated circuit (e.g., memorycell 100 or memory cell array 300A-300B, 400A-400B, 600-800 or500A-500H) using a set of masks manufactured based on one or more layoutdesigns (e.g., layout design 300A, 300B, 400A, 400B or 600-800)generated by system 1200.

System 1200 of FIG. 12 generates layout designs (e.g., layout design300A, 300B, 400A, 400B or 600-800) of memory cell 100, memory cell array200A or 200B or memory cell array 500A or 500B that occupy less areathan other approaches.

One aspect of this description relates to a method of forming a memorycell array. In some embodiments, the method includes generating a firstset of tiles extending in a first direction, generating a second set oftiles extending in the first direction, and manufacturing the memorycell array based on at least the first layout design. In someembodiments, the generating the first set of tiles includes generating afirst layout design of a first set of memory cells, each tile of thefirst set of tiles corresponds to the first layout design of the firstset of memory cells, each tile of the first set of tiles is offset froman adjacent tile of the first set of tiles in a second directiondifferent from the first direction, and each tile of the first set oftiles includes at least a first corner notch. In some embodiments, thegenerating the second set of tiles includes generating a second layoutdesign of a second set of memory cells, each tile of the second set oftiles corresponds to the second layout design of the second set ofmemory cells, each tile of the second set of tiles is offset from anadjacent tile of the second set of tiles in the second direction, andeach tile of the second set of tiles includes at least a second cornernotch. In some embodiments, each first corner notch is flush with eachsecond corner notch, each tile of the first set of tiles extends in athird direction different from the first direction and the seconddirection, the first set of tiles and the second set of tiles alternatewith each other in the second direction, and each tile of the second setof tiles extends in the third direction, and at least one of the abovegenerating operations is performed by a hardware processor, and thefirst layout design is stored in a non-transitory computer-readablemedium.

Another aspect of this description relates to a method of forming amemory cell array having a first set of memory cells. The methodincludes generating, by a processor, a layout design of the memory cellarray, the layout design corresponding to a tile having a first cornernotch and a second corner notch, and manufacturing the memory cell arraybased on the layout design. In some embodiments, the generating of thelayout design includes generating a first active region layout patterncorresponding to fabricating a first active region of the memory cellarray, the first active region layout pattern extending between thefirst corner notch and the second corner notch, and being adjacent to afirst side of a memory cell of the first set of memory cells; andgenerating a second active region layout pattern corresponding tofabricating a second active region of the memory cell array, the secondactive region layout pattern being adjacent to a second side of thememory cell opposite from the first side of the memory cell, the secondactive region layout pattern being separated from the first activeregion layout pattern in a first direction, the first active regionlayout pattern and the second active region layout pattern extending ina second direction and being located on a first layout level. In someembodiments, at least one of the above layout patterns is stored in anon-transitory computer-readable medium, and at least one of the abovegenerating operations is performed by a hardware processor.

Still another aspect of this description relates to a memory cell array.In some embodiments, the memory cell array includes a first memory cellarranged in a first row in a first direction, a second memory cellarranged in a second row in the first direction, and being separatedfrom the first memory cell in a second direction different from thefirst direction, a first word line extending in the first direction, andbeing coupled to the first memory cell, a second word line extending inthe first direction, and being coupled to the second memory cell, and afirst bit line extending in the second direction, and being coupled tothe first memory cell and the second memory cell. In some embodiments,the first memory cell corresponds to a five transistor (5T) memory cell.In some embodiments, the first memory cell includes a first activeregion having a first length in the second direction, and a secondactive region having a second length in the second direction and beingdifferent from the first length. In some embodiments, the first activeregion and the second active region extending in the second direction,being located on a first level and being separated from each other inthe first direction.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method of forming a memory cell array, themethod comprising: generating a first set of tiles extending in a firstdirection, wherein the generating the first set of tiles comprises:generating a first layout design of a first set of memory cells, eachtile of the first set of tiles corresponds to the first layout design ofthe first set of memory cells, each tile of the first set of tiles isoffset from an adjacent tile of the first set of tiles in a seconddirection different from the first direction, and each tile of the firstset of tiles includes at least a first corner notch; generating a secondset of tiles extending in the first direction, wherein the generatingthe second set of tiles comprises: generating a second layout design ofa second set of memory cells, each tile of the second set of tilescorresponds to the second layout design of the second set of memorycells, each tile of the second set of tiles is offset from an adjacenttile of the second set of tiles in the second direction, and each tileof the second set of tiles includes at least a second corner notch,wherein each first corner notch is flush with each second corner notch,each tile of the first set of tiles extends in a third directiondifferent from the first direction and the second direction, the firstset of tiles and the second set of tiles alternate with each other inthe second direction, and each tile of the second set of tiles extendsin the third direction, and at least one of the above generatingoperations is performed by a hardware processor, and the first layoutdesign is stored in a non-transitory computer-readable medium; andmanufacturing the memory cell array based on at least the first layoutdesign.
 2. The method of claim 1, wherein the first set of memory cellsare arranged in at least a first row and a second row of the memory cellarray, the first set of memory cells includes 4 memory cells, eachmemory cell of the first set of memory cells comprises a five transistor(5T) synchronous random access memory (SRAM) memory cell; and the secondset of memory cells are arranged in at least a third row and a fourthrow of the memory cell array, the second set of memory cells includes 4memory cells, each memory cell of the second set of memory cellscomprises a 5T SRAM memory cell.
 3. The method of claim 1, whereingenerating the first layout design of the first set of memory cellscomprises: generating a first portion of the first layout design, thefirst portion of the first layout design corresponding to fabricating afirst memory cell of the first set of memory cells; and generating asecond portion of the first layout design, the second portion of thefirst layout design corresponding to fabricating a second memory cell ofthe first set of memory cells, the first portion of the first layoutdesign and the second portion of the first layout design are mirrorimages of each other with respect to the second direction.
 4. The methodof claim 3, wherein generating the first layout design of the first setof memory cells further comprises: generating a third portion of thefirst layout design, the third portion of the first layout designcorresponding to fabricating a third memory cell of the first set ofmemory cells of the memory cell array; and generating a fourth portionof the first layout design, the fourth portion of the first layoutdesign corresponding to fabricating a fourth memory cell of the firstset of memory cells of the memory cell array, wherein the third portionof the first layout design and the fourth portion of the first layoutdesign are mirror images of each other with respect to the seconddirection.
 5. The method of claim 1, wherein generating the secondlayout design of the second set of memory cells comprises: generating afirst portion of the second layout design, the first portion of thesecond layout design corresponding to fabricating a first memory cell ofthe second set of memory cells of the memory cell array; and generatinga second portion of the second layout design, the second portion of thesecond layout design corresponding to fabricating a second memory cellof the second set of memory cells of the memory cell array.
 6. Themethod of claim 5, wherein generating the second layout design of thesecond set of memory cells further comprises: generating a third portionof the second layout design, the third portion of the second layoutdesign corresponding to fabricating a third memory cell of the secondset of memory cells of the memory cell array; and generating a fourthportion of the second layout design, the fourth portion of the secondlayout design corresponding to fabricating a fourth memory cell of thesecond set of memory cells of the memory cell array, wherein the firstportion of the second layout design and the third portion of the secondlayout design are mirror images of each other with respect to the thirddirection; and the second portion of the second layout design and thefourth portion of the second layout design are mirror images of eachother with respect to the third direction.
 7. The method of claim 1,wherein generating the first layout design of the first set of memorycells or generating the second layout design of the second set of memorycells comprises: generating a set of active region layout patternscorresponding to fabricating a set of active regions of the memory cellarray, each active region layout pattern of the set of active regionlayout patterns being separated from an adjacent layout pattern of theset of active region layout patterns in the third direction by a firstpitch, the set of active region layout patterns extending in the seconddirection and being located on a first layout level, wherein generatingthe set of active region layout patterns comprises: generating a firstactive region layout pattern; generating a second active region layoutpattern; generating a third active region layout pattern between thefirst active region layout pattern and the second active region layoutpattern, and generating a fourth active region layout pattern betweenthe third active region layout pattern and the second active regionlayout pattern, a length of the first active region layout pattern beingdifferent from a length of the second active region layout pattern;generating a set of gate layout patterns corresponding to fabricating aset of gate structures of the memory cell array, the set of gate layoutpatterns extending in the third direction, overlapping the set of activeregion layout patterns, and being located on a second layout leveldifferent from the first layout level; generating a first set ofconductive feature layout patterns corresponding to fabricating a firstset of conductive structures of the memory cell array, the first set ofconductive feature layout patterns extending in the third direction andbeing over at least the set of active region layout patterns or the setof gate layout patterns, each conductive feature layout pattern of thefirst set of conductive feature layout patterns being separated from anadjacent layout pattern of the first set of conductive feature layoutpatterns in at least the second direction or the third direction, andbeing located on a third layout level different from the first layoutlevel and the second layout level; and generating a first set of vialayout patterns corresponding to fabricating a first set of vias, thefirst set of via layout patterns being between the first set ofconductive feature layout patterns and at least the first active regionlayout pattern or the second active region layout pattern, and each vialayout pattern of the first set of via layout patterns being locatedwhere each conductive feature layout pattern of the first set ofconductive feature layout patterns overlaps at least the first activeregion layout pattern or the second active region layout pattern.
 8. Amethod of forming a memory cell array having a first set of memorycells, the method comprising: generating, by a processor, a layoutdesign of the memory cell array, the layout design corresponding to atile having a first corner notch and a second corner notch, wherein thegenerating of the layout design comprises: generating a first activeregion layout pattern corresponding to fabricating a first active regionof the memory cell array, the first active region layout patternextending between the first corner notch and the second corner notch,and being adjacent to a first side of a memory cell of the first set ofmemory cells; and generating a second active region layout patterncorresponding to fabricating a second active region of the memory cellarray, the second active region layout pattern being adjacent to asecond side of the memory cell opposite from the first side of thememory cell, the second active region layout pattern being separatedfrom the first active region layout pattern in a first direction, thefirst active region layout pattern and the second active region layoutpattern extending in a second direction and being located on a firstlayout level; wherein at least one of the above layout patterns isstored in a non-transitory computer-readable medium, and at least one ofthe above generating operations is performed by a hardware processor;and manufacturing the memory cell array based on the layout design. 9.The method of claim 8, wherein generating the layout design of thememory cell array further comprises: placing a set of gate layoutpatterns on a second layout level different from the first layout leveland overlapping at least the first active region layout pattern or thesecond active region layout pattern, the set of gate layout patternscorresponding to fabricating a set of gates of the memory cell array,and the set of gate layout patterns extending in the first direction;and placing a first set of conductive feature layout patterns on a thirdlayout level different from the first layout level, and being over atleast the first active region layout pattern or the second active regionlayout pattern, the first set of conductive feature layout patternscorresponding to fabricating a first set of conductive structures of thememory cell array, the first set of conductive feature layout patternsextending in the first direction, and each conductive feature layoutpattern of the first set of conductive feature layout patterns beingseparated from an adjacent layout pattern of the first set of conductivefeature layout patterns in at least the first direction or the seconddirection.
 10. The method of claim 9, wherein generating the layoutdesign of the memory cell array further comprises: placing a first setof via layout patterns between the first set of conductive featurelayout patterns and at least the first active region layout pattern orthe second active region layout pattern, the first set of via layoutpatterns corresponding to fabricating a first set of vias, the first setof vias coupling the first set of conductive structures to at least thefirst active region or the second active region, and each via layoutpattern of the first set of via layout patterns being located where eachconductive feature layout pattern of the first set of conductive featurelayout patterns overlaps at least the first active region layout patternor the second active region layout pattern; placing a second set ofconductive feature layout patterns on a fourth layout level differentfrom the first layout level, the second layout level and the thirdlayout level, the second set of conductive feature layout patternscorresponding to fabricating a second set of conductive structures ofthe memory cell array, the second set of conductive feature layoutpatterns extending in at least the first direction or the seconddirection and overlapping at least the first active region layoutpattern, the second active region layout pattern or the set of gates,and each conductive feature layout pattern of the second set ofconductive feature layout patterns being separated from an adjacentlayout pattern of the second set of conductive feature layout patternsin at least the first direction or the second direction; and placing asecond set of via layout patterns between the second set of conductivefeature layout patterns and the set of gate layout patterns, the secondset of via layout patterns corresponding to fabricating a second set ofvias, the second set of vias coupling the second set of conductivestructures to the set of gates, and a first via layout pattern of thesecond set of via layout patterns being located where a first conductivefeature layout pattern of the second set of conductive feature layoutpatterns overlaps a first gate layout pattern of the set of gate layoutpatterns.
 11. The method of claim 10, wherein generating the layoutdesign of the memory cell array further comprises: placing a third setof conductive feature layout patterns on a fifth layout level differentfrom the first layout level, the second layout level, the third layoutlevel and the fourth layout level, the third set of conductive featurelayout patterns corresponding to fabricating a third set of conductivestructures of the memory cell array, the third set of conductive featurelayout patterns extending in the first direction, and overlapping thesecond set of conductive feature layout patterns, each conductivefeature layout pattern of the third set of conductive feature layoutpatterns being separated from an adjacent layout pattern of the thirdset of conductive feature layout patterns in at least the firstdirection or the second direction; and placing a third set of via layoutpatterns between the third set of conductive feature layout patterns andthe second set of conductive feature layout patterns, the third set ofvia layout patterns corresponding to fabricating a third set of vias,the third set of vias coupling the third set of conductive structures tothe second set of conductive structures, and a first via layout patternof the third set of via layout patterns being located where a firstconductive feature layout pattern of the third set of conductive featurelayout patterns overlaps a second layout pattern of the second set ofconductive feature layout patterns.
 12. The method of claim 8, whereinthe first active region layout pattern corresponds to a first activeregion of: a first N-type transistor; the second active region layoutpattern corresponds to a second active region of: a second N-typetransistor coupled to the first N-type transistor; and a pass-gatetransistor coupled to the second N-type transistor, each of the firstN-type transistor, the second N-type transistor and the pass-gatetransistor being part of a five transistor (5T) synchronous randomaccess memory (SRAM) memory cell, and a first length of the first activeregion layout pattern in the second direction is different from a secondlength of the second active region layout pattern in the seconddirection.
 13. The method of claim 12, wherein generating the layoutdesign of the memory cell array further comprises: placing a first welllayout pattern on a second layout level different from the first layoutlevel, the first well layout pattern corresponding to fabricating afirst well of the memory cell array, the first well having a firstdopant type, the placing the first well layout pattern comprises:placing a first layout pattern adjacent to the first side of the memorycell, the first corner notch and the second corner notch, and below thefirst active region layout pattern, the first layout patterncorresponding to fabricating a first portion of the first well, and thefirst layout pattern extending in the second direction; and placing asecond layout pattern adjacent to the second side of the memory cell,and below a first portion of the second active region layout pattern,the second layout pattern corresponding to fabricating a second portionof the first well, and the second layout pattern extending in the seconddirection; and placing a second well layout pattern on the second layoutlevel, the second well layout pattern corresponding to fabricating asecond well of the memory cell array, the second well having a seconddopant type different from the first dopant type, the placing the secondwell layout pattern comprises: placing a third layout pattern betweenthe first layout pattern and the second layout pattern, and below athird active region layout pattern and a fourth active region, the thirdlayout pattern corresponding to fabricating a first portion of thesecond well, and the third layout pattern extending in the seconddirection; and placing a fourth layout pattern adjacent to the secondside of the memory cell, and below a second portion of the second activeregion layout pattern, the fourth layout pattern corresponding tofabricating a second portion of the second well, and the fourth layoutpattern extending in the second direction.
 14. The method of claim 8,wherein the first active region layout pattern corresponds to a firstactive region of: a first P-type transistor; the second active regionlayout pattern corresponds to a second active region of: a second P-typetransistor coupled to the first P-type transistor; and a pass-gatetransistor coupled to the second P-type transistor, each of the firstP-type transistor, the second P-type transistor and the pass-gatetransistor being part of a five transistor (5T) synchronous randomaccess memory (SRAM) memory cell, and a first length of the first activeregion layout pattern in the second direction is different from a secondlength of the second active region layout pattern in the seconddirection, and the second active region layout pattern extending from aside of the layout design to another side of the layout design.
 15. Themethod of claim 14, wherein generating the layout design of the memorycell array further comprises: placing a first well layout pattern on asecond layout level different from the first layout level, the firstwell layout pattern corresponding to fabricating a first well of thememory cell array, the first well having a first dopant type, theplacing the first well layout pattern comprises: placing a first layoutpattern adjacent to the first side of the memory cell, the first cornernotch and the second corner notch, and below the first active regionlayout pattern, the first layout pattern corresponding to fabricating afirst portion of the first well, and the first layout pattern extendingin the second direction; and placing a second layout pattern adjacent tothe second side of the memory cell, and below the second active regionlayout pattern, the second layout pattern corresponding to fabricating asecond portion of the first well, and the second layout patternextending in the second direction; and placing a second well layoutpattern on the second layout level, being between the first layoutpattern and the second layout pattern, and below a third active regionlayout pattern and a fourth active region, the second well layoutpattern corresponding to fabricating a second well of the memory cellarray, and the second well having a second dopant type different fromthe first dopant type.
 16. A memory cell array comprising: a firstmemory cell arranged in a first row in a first direction; a secondmemory cell arranged in a second row in the first direction, and beingseparated from the first memory cell in a second direction differentfrom the first direction; a first word line extending in the firstdirection, and being coupled to the first memory cell; a second wordline extending in the first direction, and being coupled to the secondmemory cell; and a first bit line extending in the second direction, andbeing coupled to the first memory cell and the second memory cell;wherein the first memory cell corresponds to a five transistor (5T)memory cell, and the first memory cell comprises: a first active regionhaving a first length in the second direction; and a second activeregion having a second length in the second direction and beingdifferent from the first length, the first active region and the secondactive region extending in the second direction, being located on afirst level and being separated from each other in the first direction.17. The memory cell array of claim 16, further comprising: a set ofgates extending in the first direction, overlapping the first activeregion and the second active region, and being located on a second leveldifferent from the first level; a first set of conductive structuresextending in at least the first direction or the second direction, andover at least the first active region or the second active region, eachconductive structure of the first set of conductive structures beingseparated from an adjacent conductive structure of the first set ofconductive structures in at least the first direction or the seconddirection, and being located on a third level different from the firstlevel; a second set of conductive structures extending in at least thefirst direction or the second direction, over the first active region,the second active region and the set of gates, each conductive structureof the second set of conductive structures being separated from anadjacent conductive structure of the second set of conductive structuresin at least the first direction or the second direction, and beinglocated on a fourth level different from the first level, the secondlevel and the third level; a first set of vias between the first set ofconductive structures and the second set of conductive structures, thefirst set of vias coupling the first set of conductive structures to thesecond set of conductive structures, and at least one via of the firstset of vias being located where at least one conductive structure of thesecond set of conductive structures overlaps at least one of the oneconductive structure of the first set of conductive structures; and asecond set of vias between the set of gates and the second set ofconductive structures, the second set of vias coupling the set of gatesto the second set of conductive structures, and a first via of thesecond set of vias being located where a first conductive structure ofthe second set of conductive structures is over a first gate of the setof gates.
 18. The memory cell array of claim 17, further comprising: athird set of conductive structures extending in the first direction, andoverlapping the second set of conductive structures, each conductivestructure of the third set of conductive structures being separated froman adjacent structure of the third set of conductive structures in atleast the first direction or the second direction, and being located ona fifth level different from the first level, the second level, thethird level and the fourth level; and a third set of vias between thethird set of conductive structures and the second set of conductivestructures, the third set of vias coupling the third set of conductivestructures to the second set of conductive structures, and a first viaof the third set of vias being located where a first conductivestructure of the third set of conductive structures is over a secondconductive structure of the second set of conductive structures.
 19. Thememory cell array of claim 16, further comprising: a first well having afirst dopant type, and being located on at least the first level, thefirst well comprising: a first portion extending in the seconddirection, being adjacent to a first side of the first memory cell, andthe first active region being embedded in the first portion of the firstwell; and a second portion extending in the second direction, beingadjacent to a second side of the first memory cell opposite from thefirst side of the first memory cell, and the second active region beingembedded in the second portion of the first well; and a second wellhaving a second dopant type different from the first dopant type, andthe second well being between the first portion of the first well andthe second portion of the first well; a third active region embedded inthe second well; and a fourth active region embedded in the second well,the third active region being between the first active region and thefourth active region, and the fourth active region being between thethird active region and the second active region.
 20. The memory cellarray of claim 16, further comprising: a first well having a firstdopant type, and being located on at least the first level, the firstwell comprising: a first portion of the first well extending in thesecond direction, being adjacent to a first side of the first memorycell, and the first active region being embedded in the first portion ofthe first well; and a second portion of the first well extending in thesecond direction, being adjacent to a second side of the first memorycell opposite from the first side of the first memory cell; and a secondwell having a second dopant type different from the first dopant type,and the second well comprising: a first portion of the second wellextending in the second direction, and being adjacent to the firstportion of the first well; and a second portion of the second wellextending in the second direction, and being adjacent to each of thefirst portion of the second well, the second portion of the first welland the second side of the first memory cell, wherein the second activeregion comprises: a first portion of the second active region embeddedin the second portion of the first well; and a second portion of thesecond active region embedded in the second portion of the second well,and being aligned with the first portion of the second active region inthe second direction; a third active region embedded in the firstportion of the second well; and a fourth active region embedded in thefirst portion of the second well, the third active region being betweenthe first active region and the fourth active region, and the fourthactive region being between the third active region and the secondactive region.